Log Calculator Or Logarithmic Calculator Online

The logarithm, or log, is the inverse of the mathematical operation of exponentiation. This means that the log of a number is the number that a fixed base has to be raised to in order to yield the number. Conventionally, log implies that base 10 is being used, though the base can technically be anything. When the base is e, ln is usually written, rather than log_e. log₂, the binary logarithm, is another base that is typically used with logarithms. If for example:

x = b^y; then y = log_bx; where b is the base

Each of the mentioned bases are typically used in different applications. Base 10 is commonly used in science and engineering, base e in math and physics, and base 2 in computer science.

Basic Log Rules:

When the argument of a logarithm is the product of two numerals, the logarithm can be re-written as the addition of the logarithm of each of the numerals.

log_b(x × y) = log_bx + log_by
EX: log(1 × 10) = log(1) + log(10) = 0 + 1 = 1

When the argument of a logarithm is a fraction, the logarithm can be re-written as the subtraction of the logarithm of the numerator minus the logarithm of the denominator.

log_b(x / y) = log_bx - log_by
EX: log(10 / 2) = log(10) - log(2) = 1 - 0.301 = 0.699

If there is an exponent in the argument of a logarithm, the exponent can be pulled out of the logarithm and multiplied.

log_bx^y = y × log_bx
EX: log(2⁶) = 6 × log(2) = 1.806

It is also possible to change the base of the logarithm using the following rule.

logb(x) =

logk(x) logk(b)

EX: log10(x) =

log2(x) log2(10)

To switch the base and argument, use the following rule.

logb(c) =

1 logc(b)

EX:   log5(2) =

1 log2(5)

Other common logarithms to take note of include:

log_b(1) = 0
log_b(b) = 1
log_b(0) = undefined
lim_x→0+log_b(x) = - ∞
ln(e^x) = x

Body Mass Index or BMI Calculator Online

The Body Mass Index (BMI) Calculator can be used to calculate BMI value and corresponding weight status while taking age into consideration. Use the "Metric Units" tab for the International System of Units or the "Other Units" tab to convert units into either US or metric units. Note that the calculator also computes the Ponderal Index in addition to BMI, both of which are discussed below in detail.

Reference

BMI is a measurement of a person's leanness or corpulence based on their height and weight, and is intended to quantify tissue mass. Although BMI has limitations in that it is an estimate that cannot take body composition into account, it can be used as a general indicator of a healthy body weight based on a person's height. The value obtained from the calculation of BMI is widely used to categorize whether a person is underweight, normal weight, overweight, or obese depending on what range the value falls between. These ranges of BMI vary based on factors such as region and age, and are sometimes further divided into subcategories such as severely underweight or very severely obese. As previously mentioned however, due to a wide variety of body types as well as distribution of muscle, bone mass, and fat, BMI should be considered along with other measurements rather than being used as the sole method for determining a person's "healthy" body weight.

Body Mass Index Formula

Below are the equations used for calculating BMI in the International System of Units (SI) and the US customary system (USC) using a 5'10", 160-pound individual as an example:

USC Units: BMI = 703× mass (lbs) height2 (in)  = 703× 160 702  = 22.96 kg m2 SI, Metric Units: BMI =  mass (kg) height2 (m)  =  72.57 1.782  = 22.90 kg m2

Ponderal Index

The Ponderal Index (PI) is similar to BMI in that it measures the leanness or corpulence of a person based on their height and weight. The main difference between the PI and BMI is the cubing rather than squaring of the height in the formula (provided below). While BMI can be a useful tool when considering large populations, it is not reliable for determining leanness or corpulence in individuals. Although the PI suffers from similar considerations, the PI is more reliable for use with very tall or short individuals, while BMI tends to record uncharacteristically high or low body fat levels for those on the extreme ends of the height and weight spectrum. Below is the equation for computing the PI of an individual using USC, again using a 5'10", 160-pound individual as an example:

USC Units: PI =  height (in) ∛mass (lbs)  =  70 ∛160  = 12.89 in ∛lbs SI, Metric Units: PI =  mass (kg) height3 (m)  =  72.57 1.783  = 12.87 kg m3

 aa Adult BMI calculator based on 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. BMI classification. World Health Organization. Adapted by Mayo Foundation for Medical Education and Research. Child BMI calculator based on clinical growth charts. Centers for Disease Control and Prevention. Adapted by Mayo Foundation for Medical Education and Research. Privacy assurance: Information that you enter won't be saved or sent to any website.

Scientific Calculator Online

Scientific calculator allows you to perform complex calculations using various trigonometric functions: sine, cosine, tangent, cotangent. Calculator can increase the number to a power, calculate the logarithm of the number. Basic commands (numbers, multiplication, division, addition, subtraction, equality, reset) can be entered using the mouse as well as using the numeric keypad (top or side). Detailed instructions for working with scientific calculator, see the bottom of the page.

0 sincostanDegRad sin-1cos-1tan-1πe xyx3x2ex10x y√x3√x√xlnlog ()1/x%n! 789+MS 456–M+ 123×M- 0.EXP÷MR ±RNDC=MC

powered by calculator.net

How to work with a scientific calculator:

• Functions of the standard buttons [ 0 ], [ 1 ], [ 2 ], ... [ 9 ] - standard numeric keypad; 
• [ 00 ] - key to enter the 2 zeros; 
• [ → ] - delete the last entered character is displayed; 
• [ +/- ] - changing the mathematical signs of the display on the opposite; 
• [ + ] - addition, 
• [ - ] - subtraction, 
• [ х ] - multiplication, 
• [ ÷ ] - division; 
• [ % ] - calculate interest; 
• [ M+ ] - stored in the memory with the sign [ + ] ; 
• [ M- ] - stored in the memory with the sign [ - ] ; 
• [ MR ] - get the contents of memory; 
• [ MC ] - clear the memory; 
• [ AC ] - reset the last value and clear the memory ; 
• [ C ] - reset the last digit of the; 

 Calculator buttons for performing trigonometric functions

• [ sin ] - sine of the angle, 
• [ cos ] - cosine of the angle, 
• [ tg ] - tangent of the angle, 
• [ ctg ] - cotangent of the angle; 
• [ asin ] - arc sine of the angle, 
• [ acos ] - arc cosine of the angle, 
• [ atg ] - arc tangent of the angle, 
• [ actg ] - arc cotangent of the angle; 
• [ π ] - mathematical constant, the ratio of the circumference to the diameter of the circle; 
• [ e ] - mathematical constant, the Euler number; 
• [ Xʸ ] - raise to higher power; 
• [ √ ] - square root; 

Examples of calculation of interest 
Calculation of percentage of the number of - 500 [ x ] 25 [ % ] Result - 125.
Deduction percentage of the number - 500 [ - ] 25 [ % ] Result - 375.
Adding percentage to the number - 500 [ + ] 25 [ % ] Result - 625.

Entering commands from the computer keyboard
To use the calculator you can use any keys: how keys are on top, and separate numeric keypad located on the right.

• To enter [ = ], you can use the [Enter]. 
• To erase the last character you can use the key to erase the last character [ Backspace ] (arrow keys). 
• To enter the sign [ + ] you can use either the [ + ] key at the top or press the [ + ] on the numeric keypad on the right. 
• To enter the sign [ - ] you can use either the [ - ] key at the top or press the [ - ] on the numeric keypad on the right. 
• To enter a [ x ] (multiplication) you can use the [ * ] key on the numeric keypad to the right or a combination of keys[ * ] and [ Shift ]. 
• To enter a [ ÷ ] (divide) you can use the [ / ] key on the numeric keypad to the right or a combination of keys [ : ] and [ Shift ].

F-Distribution

The F distribution calculator makes it easy to find the cumulative probability associated with a specified f value. Or you can find the f value associated with a specified cumulative probability. What are degrees of freedom? Degrees of freedom can be described as the number of scores that are free to vary. For example, suppose your friend tossed three dice, and the total score added up to 12. If your friend told you that he rolled a 3 on the first die and a 5 on the second, then you know that the third die must be a 4 (otherwise, the total would not add up to 12). In this example, 2 die are free to vary while the third is not. Therefore, there are 2 degrees of freedom. In many situations, the degrees of freedom are equal to the number of observations minus one. Thus, if the sample size were 20, there would be 20 observations; and the degrees of freedom would be 20 minus 1 or 19. What is f-value? An f value (also known as an f statistic) is a random variable that has an F distribution. Here are the steps required to compute an f value: Select a random sample of size n1 from a normal population, having a standard deviation equal to σ1. Select an independent random sample of size n2 from a normal population, having a standard deviation equal to σ2. The f value is the ratio of s12/σ12 and s22/σ22. Thus, f = [ s12/σ12 ] / [ s22/σ22]

Derivative Solver Calculator

The Derivative Calculator lets you calculate derivatives of functions online — for free! Our calculator allows you to check your solutions to calculus exercises. The Derivative Calculator supports computing first, second, .... fifth derivatives as well as differentiating functions with many variables (partial derivatives), implicit differentiation and calculating roots/zeros. You can also check your answers! Interactive graphs/plots help visualize and better understand the functions. How the Derivative Calculator Works For those with a technical background, the following section explains how the Derivative Calculator works. First, a parser analyzes the mathematical function. It transforms it into a form that is better understandable by a computer, namely a tree (see figure below). In doing this, the Derivative Calculator has to respect the order of operations. A specialty in mathematical expressions is that the multiplication sign can be left out sometimes, for example we write "5x" instead of "5*x". The Derivative Calculator has to detect these cases and insert the multiplication sign. The parser is implemented in JavaScript, based on the Shunting-yard algorithm, and can run directly in the browser. This allows for quick feedback while typing by transforming the tree into LaTeX code. MathJax takes care of displaying it in the browser. When the "Go!" button is clicked, the Derivative Calculator sends the mathematical function and the settings (differentiation variable and order) to the server, where it is analyzed again. This time, the function gets transformed into a form that can be understood by the computer algebra system Maxima.

Grade Point Average (GPA) Calculator

How to Calculate Your Grade Point Average (GPA)

Your grade point average (GPA) is calculated by dividing the total amount of grade points earned by the total amount of credit hours attempted. Your grade point average may range from 0.0 to a 4.0.

For example:

A = 4.00 grade points
A- = 3.70 grade points
B+ = 3.33 grade points
B = 3.00 grade points
B- = 2.70 grade points
C+ = 2.30 grade points
C = 2.00 grade points
C- = 1.70 grade points
D+ = 1.30 grade points
D = 1.00 grade points
D- = 0.70 grade points

WF/F=0 grade points

Pass or Not passed in the courses are not factored in the GPA calculation
I (Incompletes) and W (Withdrawals) also get zero grade points and therefore do not have any effect on the GPA.

Example Student Transcript
Course	Credit Hours	Grade	Grade Points
Biology Biology Lab English 101 Mathematics	3 1 3 3	A B C F	12 3 6 0
10 Total Credit Hours Attempted			21 Total Grade Points

To get the example student's GPA, the total grade points are divided by the total credit hours attempted.

Total Grade Points Total Credit Hours Attempted

divided by

21 10

= 2.10

You can total your current semester courses and credits with our online GPA Calculator (above).

To calculate your cumulative G.P.A., total the credit hours and then the grade points from all semesters. Divide the total grade points by the total credit hours. You can also use this online tool.

If you want to raise your GPA, an additional calculator helps you determine how many credit hours and what grade average you will need to raise your current GPA.

Source: Back2College

Percentage Calculator Online

Percentage Calculator is a free online tool to help you calculate percentages.

Enter values below and find out accurate percentages

What is % of ?

%

is what percent of ?

%

What is the percentage increase/decrease
from to ?

%

Hint: You can use "Tab" to move from one field to the next. Press enter to calculate.

Simple Graphing Calculator Online

About Graphing Calculator                                                                                            Source: Wikipedia

A graphing calculator (also graphics / graphic calculator) typically refers to a class of handheld scientific calculators that are capable of plotting graphs, solving simultaneous equations, and performing numerous other tasks with variables. Most popular graphing calculators are also programmable, allowing the user to create customized programs, typically for scientific/engineering and education applications. Due to their large displays intended for graphing, they can also accommodate several lines of text and calculations at a time.

Some of the more recent graphing calculators are capable of color output, and also feature animated and interactive drawing of math plots (2D and 3D), other figures such as animated Algebra theorems, preparation of documents which can include these plots and drawings, etc. This is giving the new graphing calculators a presence even in high school courses where they were formerly disallowed. Some calculator manufacturers also offer computer software for emulating and working with handheld graphing calculators.

Many graphing calculators can be attached to devices like electronic thermometers, pH gauges, weather instruments, decibel and light meters, accelerometers, and other sensors and therefore function as data loggers, as well as WiFi or other communication modules for monitoring, polling and interaction with the teacher. Student laboratory exercises with data from such devices enhances learning of math, especially statistics and mechanics.

Graphing calculators can be sub-divided into two categories (both need the graphical display):

1. Numerical (or just graphing) Calculators - non-CAS and producing numerical results, at most represented as a fraction. In some countries, graphing calculators are not permitted in high school science tests or certain basic math tests. See examples below.

2. CAS (or symbolic) Calculators - most advanced calculators capable of producing a symbolic result (in expression or equation form), usually utilizing a Computer Algebra System (CAS). Symbolic/CAS calculators are posing a challenge to high school and undergraduate educators. They can make math easier to learn for high schoolers, provided school curriculum evolves towards this advantage.[1][2] Testing based on tedious hand calculation is also being forced to evolve towards more creative testing.[3] Such tests are often more challenging and expensive to design and can't be recycled as much, but encourage a genuine deeper appreciation of the art of mathematics and critiqueing a fallacy. CAS calculators are therefore usually permitted only in select advanced math or calculus tests, thereby being more of a classroom learning tool for many users who then switch to a permitted and speedy numerical non-CAS graphing or scientific calculator for tests and exams.

Check you understanding of Scalar and Vector by using the widget the below. Is it Scalar? Or is it Vector?

About Scalar & Vector:                                                                                             From Wikipedia

In physics, a scalar is a physical quantity that is unchanged by coordinate system rotations or reflections (in Newtonian mechanics), or by Lorentz transformations or space-time translations (in relativity).

A scalar is a quantity which can be described by a single number, unlike vectors, tensors, etc. which are described by several numbers which describe magnitude and direction. A related concept is a pseudoscalar, which is invariant under proper rotations but (like a pseudovector) flips sign under improper rotations. The concept of a scalar in physics is essentially the same as in mathematics.

An example of a scalar quantity is temperature: the temperature at a given point is a single number. Velocity, on the other hand, is a vector quantity: velocity in three-dimensional space is specified by three values; in a Cartesian coordinate system the values are the speeds relative to each coordinate axis.

A Vector on the other hand is a mathematical quantity with both a magnitude and direction.

More on Scalar & Vectors.

Scalars and Vectors in Physics is a mathematical science. The underlying concepts and principles have a mathematical basis. Throughout the course of our study of physics, we will encounter a variety of concepts that have a mathematical basis associated with them. While our emphasis will often be upon the conceptual nature of physics, we will give considerable and persistent attention to its mathematical aspect.

The motion of objects can be described by words. Even a person without a background in physics has a collection of words that can be used to describe moving objects. Words and phrases such as going fast, stopped, slowing down, speeding up, and turning provide a sufficient vocabulary for describing the motion of objects. In physics, we use these words and many more. We will be expanding upon this vocabulary list with words such as distance, displacement, speed, velocity, and acceleration. As we will soon see, these words are associated with mathematical quantities that have strict definitions. The mathematical quantities that are used to describe the motion of objects can be divided into two categories. The quantity is either a vector or a scalar. These two categories can be distinguished from one another by their distinct definitions:

Scalars are quantities that are fully described by a magnitude (or numerical value) alone.

Vectors are quantities that are fully described by both a magnitude and a direction.

The remainder of this lesson will focus on several examples of vector and scalar quantities (distance, displacement, speed, velocity, and acceleration). As you proceed through the lesson, give careful attention to the vector and scalar nature of each quantity. As we proceed through other units at The Physics Classroom Tutorial and become introduced to new mathematical quantities, the discussion will often begin by identifying the new quantity as being either a vector or a scalar.

Convert from Newton to Kilogram (kg)

Use the above calculator to convert units of force from Newton to Kg and vice versa.
ConvertUnits.com provides an online conversion calculator for all types of measurement units. You can find metric conversion tables for SI units, as well as English units, currency, and other data. Type in unit symbols, abbreviations, or full names for units of length, area, mass, pressure, and other types. Examples include mm, inch, 100 kg, US fluid ounce, 6'3", 10 stone 4, cubic cm, metres squared, grams, moles, feet per second, and many more!

About Newton:                                                                                                           From Wikipedia

The newton (symbol: N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.

In 1946, Conférence Générale des Poids et Mesures (CGPM) resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate of 1 metre per second squared. The 9th CGPM, held in 1948, then adopted the name "newton" for this unit in resolution 7. This name honors the English physicist and mathematician Isaac Newton, who laid the foundations for most of classical mechanics. The newton thus became the standard unit of force in le Système International d'Unités (SI), or International System of Units.

Newton's second law of motion states that F = ma, where F is the force applied, m is the mass of the object receiving the force, and a is the acceleration of the object. 

The newton is therefore:

where the following symbols are used for the units:

N: newton

kg: kilogram

m: metre

s: second.

In dimensional analysis:

where:

M: mass

L: length

T: time.

This SI unit is named after Isaac Newton. As with every International System of Units (SI) unit whose name is derived from the proper name of a person, the first letter of its symbol is upper case (N). However, when an SI unit is spelled out in English, it should always begin with a lower case letter (newton), except in a situation where any word in that position would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Note that "degree Celsius" conforms to this rule because the "d" is lowercase.

About Kilogram (kg):                                                                                                From Wikipedia

The kilogram or kilogramme (SI unit symbol: kg; SI dimension symbol: M), is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype of the Kilogram (IPK). The avoirdupois (or international) pound, used in both the Imperial system and U.S. customary units, is defined as exactly 0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds.

The gram was originally defined in 1795 as the mass of one cubic centimeter of water at 4°C, making the kilogram equal to the mass of one liter of water. The prototype kilogram, manufactured in 1799 and from which the current kilogram is based has a mass equal to the mass of 1.000025 liters of water.

Movimiento Armonico Simple

Derivative Calculator and Solver

This Derivative Calculator & Derivative Solver lets you calculate derivatives of functions online!

This widget will find the nth (up to the 10th) derivative of any function

The calculator supports computing upto the 10th derivative as well as differentiating functions.

With the Derivative Calculator you can check your solutions to calculus exercises. Even though it can show a step by step differentiation, it is not meant to be used for cheating!

For Step-by-Step instructions click on Step-by-Step in the 1st page of the result.

What is a Derivative?

In calculus, a branch of mathematics, the derivative is a measure of how a function changes as its input changes. Loosely speaking, a derivative can be thought of as how much one quantity is changing in response to changes in some other quantity; for example, the derivative of the position of a moving object with respect to time is the object's instantaneous velocity.

The derivative of a function at a chosen input value describes the best linear approximation of the function near that input value. Informally, the derivative is the ratio of the infinitesimal change of the output over the infinitesimal change of the input producing that change of output. For a real-valued function of a single real variable, the derivative at a point equals the slope of the tangent line to the graph of the function at that point. In higher dimensions, the derivative of a function at a point is a linear transformation called the linearization. A closely related notion is the differential of a function.

The process of finding a derivative is called differentiation.

From Wikipedia

Ionic Equation Calculator

Net Ionic Equation Calculator

To write a net ionic equation you have to write the balanced molecular equation. then write the balanced complete ionic equation. Cross out the present spectator ions. What is left is the Net ionic equation.

From Wikipedia:
An ionic equation is a chemical equation in which electrolytes are written as dissociated ions. Ionic equations are used for single and double displacement reactions that occur in aqueous solutions. For example in the following precipitation reaction: CaCl2(aq) + 2AgNO3(aq) --> Ca(NO3)2(aq) + 2AgCl(s)

The full ionic equation would be: Ca²⁺ + 2Cl⁻ + 2Ag⁺ + 2NO3⁻ ---> Ca2⁺ + 2NO3⁻ + 2AgCl(s)

and the net ionic equation would be:2Cl⁻(aq) + 2Ag⁺(aq) --> 2AgCl(s)

or, in reduced balanced form,Ag⁺ + Cl⁻ --> AgCl(s)

In this aqueous reaction the Ca2⁺ and the NO3⁻ ions remain in solution and are not part of the reaction. They are termed spectator ions and do not participate directly in the reaction, as they exist with the same oxidation state on both the reactant and product side of the chemical equation. They are only needed for charge balance of the original reagents.

In a neutralization or acid / base reaction, the net ionic equation will usually be:H⁺ + OH⁻ --> H2O

There are a few acid/base reactions that produce a precipitate in addition to the water molecule shown above. An example would be the reaction of barium hydroxide with phosphoric acid because the insoluble salt barium phosphate is produced in addition to water.

Double displacement reactions that feature a carbonate reacting with an acid have the net ionic equation:2 H⁺ + CO3²⁻ --> H2O + CO2

If every ion is a "spectator ion", then there was no reaction, and the net ionic equation is null.

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Best Results From Yahoo Answers Youtube

From Yahoo Answers

Question:a) 2AgNO3 (aq) + Na2SO4 (aq) ---> How would i write the ionic and net ionic equation for this without knowing the charge for Ag (silver)? I'm really lost =[ can someone give me an explaination as well? that would be really helpful!

Answers:Ag is +1 and Na is also +1 (remember HNO3 where H is +1)

Question:Write a balanced formula equation, complete ionic equation, and net ionic equation for the reaction between: (Be sure to include phases.) a. an alkaline earth salt and sulfuric acid, being sure to identify the precipitate. b a halogen with a less active halide, being sure to identify which is oxidized and reduced.

Answers:(A) Among the alkaline earth metals you can chose the soluble salts of calcium, strontium or barium as one of the reactants, because the sulfates of these salts are slightly soluble. The least soluble one is barium sulfate and suppose we choose it as the product. All nitrates of metals are soluble, therefore we can choose barium nitrate as the reactant. Formula equation; Ba(NO3)2(aq) + H2SO4(aq) -------> BaSO4(s) + 2HNO3(aq) Ionic equation: Ba^2+(aq) + 2NO3^-(aq) + 2H^+(aq) + SO4^2-(aq) -------> BaSO4(s) + 2H^+(aq) + 2NO3^-(aq) Net ionic equation: (obtained by eliminating the spectator ions from both sides) Ba^2+(aq) + SO4^2-(aq) -------> BaSO4(aq) (B) Activity of halogens decreases from top to bottom within the group ( F > Cl > Br > I ) In the elemental state all halogens are diatomic molecules. F2 and Cl2 are gases, Br2 is liquid and I2 is solid. F2 replaces all other halogens. Cl2 replaces Br2 and I2. Br2 can only replace I2. Since I2 is the least active one it cannot replace any halogen. Formula equation; Cl2(g) + 2NaBr(aq) -------> 2NaCl(aq) + Br2(l) (note: all salts of sodium, potassium and ammonium are soluble) Ionic equation: Cl2(g) + 2Na^+(aq) + 2Br^-(aq) ------> 2Na^+(aq) + 2Cl^- (aq) + Br2(l) Net ionic equation: Cl2(g) + 2Br^-(aq) ------>2Cl^- (aq) + Br2(l) As it is clearly seen from the net ionic equation, Cl2 is reduced from 0 to -1 and Br^- is oxidized from -1 to 0.

From Youtube:

Net Ionic Equation :Free Science Help at Brightstorm! brightstorm.com How to write a net ionic equation.