Math Features

How To: Derive the area of a circle

This video is about deriving the area of a circle of radius 'r' using polar co-ordinate. First, we draw a circle and its radius 'r'. Then draw another radius close to it, so that it forms a small triangle-like figure. To find the area of the complete circle, divide the circle into similar small triangles. The area of each triangle is given by half the product of its perpendicular and the base. We give the angle between the two radii as d?. We get the area of the small triangle by substituting...

How To: Compare methods of solving quadratic equations

In this video the instructor shows the different methods of solving quadratic equations. There are many methods to solve quadratic equations each with its pros and cons, each method suitable for a particular situation. The first method to solve quadratic equation is factoring. The advantage of using this method is that it is quick and easy. But the problem is not all equations can be factored very easily. This method requires a lot of practice and intuition. Use this method when the discrimin...

How To: Solve reverse percentage problems

We know the method for answering the question "What is the x percent of y" but, what about the answer to the following question "The x percent discounted price of an article is y. Find the original price." This is a reverse percentage problem that can be solved using the method shown in this video. This video contains three reverse percentage problems. The first two problems are essentially of the same type as explained above. A simple and easy to understand method of finding the original pri...

How To: Calculate angles formed between transversals and parallel lines in geometry

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to calculate the value of angles formed between transversals and parallel lines in basic geometry.

How To: Find intercepts on a calculator TI-83

NotesCollegeAlgebra teaches you how to find intercepts on a calculator TI-83. You start with y plus 1.7 equals .8 times x squared plus 1.4 times x. First you subtract 1.7 from both sides, you get y alone on one side. The window should be set to -5...5, -5...5. X scale should be at 1, y scale at 1 and x rez at 1. Make a graph for it, like a parabola. Use trace to get y intercept at negative 1.7. The x intercept is about .85. Continue to use the calculator to get all the values that you need.

How To: Find the percent change using proportions

In this video, the instructor shows how to identify the percentage change using proportions. When a given quantity increases or decreases by certain amount then we can calculate the percentage change in the quantity, which can be either increase or decrease based on the new value of the quantity. To solve these kind of situations you should know that the ratio of amount of increase (or decrease) of an amount to its original amount is equal to the ratio of percentage increase (or decrease) to ...

How To: Find the equation of the axis of symmetry

This video is about the Equation of Axis of Symmetry, The video is about the equation which is x = 3/4. In order to score correct marks for this equation, the gentleman in the video describes how and where to write x = 3/4, he says it has to be written on the graph, and the video contains the example graph. It is quite an interesting educational video, especially for those doing mathematics and want to learn more online, this video is very useful for students. There is more about the equation...

How To: Find the domain of a function without graphing

Want to find the domain of a function without graphing it? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

How To: Solve problems involving rational equations in algebra

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to find answers to rational equation problems in algebra.

How To: Find the domain and range of a function

Need to calculate the domain and range of a function in algebra? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

How To: Find the vertical asymptotes of a rational function

Need help figuring out how to find the vertical and horizontal asymptotes of a rational function? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

How To: Solve advanced ratio problems in algebra

Need to know how to solve complex ratio problems in basic algebra? From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn a system for finding solu...

How To: Calculate square roots on paper the easy way

Perhaps not as easy as using a calculator, but easy nevertheless! With mathematics, as with anything else, not everyone progresses at the same rate. Happily, in the age of Internet video tutorials, this isn't a problem. Those who progress quickly can go beyond what's being taught them and those who are struggling likewise have all the time in the world to catch up. With this free video math lesson, you'll learn how to find square roots by hand.

How To: Simplify square roots w/ product & quotient rules

In this math tutorial, you will learn how to simplify square roots with product and quotient rules. To begin, you will need to multiply the square roots so that the two square roots in your equation are reduced down into one. The rule for non-negative "A" and "B" is that the square root of "A" multiplied by the square root of "B" yields the square root of A x B.

How To: Find r-value & equation of regression line w/ EL531W

Need a little help in your Statistics class? In this statistics tutorial hosted by The Free Math Tutor, a demonstration of how to use the Sharp EL531W calculator to find the correlation coefficient (r-value) and the equation of a regression line is given. Want some more practice? For exercises and answer sheets, go here.

How To: Deal with brackets in polynomials

This how-to video shows viewers how to solve math problems with brackets in polynomials. The person in the video teaches people how to solve the problem with a positive sign before the brackets. This segment does not show how to solve the trickier problem where there is a negative sign in front of the brackets. The tutor shows everything from removing the bracket due to the positive sign, to combining the similar terms for the result of the problem. This video can help anybody deal with brack...

How To: Find the perimeter of a shape

Two dimensional objects are measured in terms of perimeter and areas. A perimeter of a two dimensional object is the distance around that object. If you want to find the perimeter of an object, all you need to do is add up each one of the lengths of sides of that object. If you have a small figure like triangle, first compute the length of the three sides. Now adding these three sides gives you the perimeter of the triangle. A larger or more complicated shape might have more number of sides. ...

How To: Do long division with different approaches

Taking equal groups, in our case, 7 out of the whole number, in this case 364 involves guessing. A shorter method involves taking groups, in our case, 7 out of each individual number 3, 6 and 4. If you cannot take 7 out of a number, you will subtract 0 from that number and carry down the next number. For example, you cannot take 7 from 3, so you will subtract 3-0 with the answer being 3 and carry down the next number, 6, giving you 36. You can take 5 groups of 7 out. 5 groups of 7 equals 35, ...

How To: Clear decimals from a linear equation

Need instructions on how to remove decimal values from a linear equation in algebra? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

How To: Calculate and solve for density

Density is a means of representing how much mass is contained in the body of an object. The basic formula is: Density (D) = Mass (M) / Volume (V) so D=M/V. Density is important to know for buoyancy and to understand how heavy an object is. This video will show you three examples of measuring density so you can learn and put it to good use.

How To: Graph negative numbers on number line

The video begins with a piece of paper with questions 6 and 7 on from section 1.3. The narrator introduces these two questions as both having to do with graphing on a number line. Starting with question 6, which asks the person to graph -11/4 on a number line, the narrator draws a number line with the numbers up to -5 on the left, up to +5 on the right of 0 in the middle. She starts by showing -3 as an example, and then draws a black dot on the line at the point of the number 3. She then illu...

How To: Determine math proportions with the Square-Cube Law

Ever watch a cheesy movie and say "That monster is so FAKE!" but not really understand why? Well monstrous monsters are governed by a little biological rule called the Square-Cube Law, a scientific term combining math, anatomy and physics into one educational tool to recognize theatrical baloney when you see it. Just watch this video to see the explanation of the Cube-Square Rule, how it works and its ramifications for our favorite B-Movie pet monsters.

How To: Evaluate fractions containing variables

This video is a great one on learning about evaluating fractions. The voice explains how to first plug in the numbers given for each variable in the fractions. He also explains the importance of simplifying the top and bottom first before simplifying the entire fraction. He also explains ways that would not be helpful in solving the problem and comparing that with the correct way. Then he notes the use of your simple math rules to find the answer. Excellent video for viewers.

How To: Find the area of a rectangle

The area of a rectangle is the basis for all geometry. You will need to know how to do this in order to better understand other objects. This video tutorial will show you the formula for area of a rectangle and how to use it. Don't be confused in math class anymore.

How To: Understand fractions with patterns

This is an educational site where we can learn about math lessons with example videos, interactive practice problems and can do self-test. The associate teacher in the video teaches us about fraction problems. She has written four numbers on the board, which is 1 1/4, 1 1/2, 1 3/4, and 2. She explains how to find the next three numbers following the same pattern. The teacher in the video tells that the key in solving the problem is to think of 1 1/2 as 1 2/4. Each number in the given problem ...

How To: Solve mathematical functions and graphs

Check out this instructional math video that demonstrates how to calculate mathematical functions and graphs. In this 9th lesson, learn how to solve on SAT Algebra problems using the Official SAT Study Guide (as always). Here are the math problems and their page numbers that this video covers:

How To: Solve problems with inverse functions

In this video the instructor teaches about inverse functions. Normally in inverse functions problems you are given a function that has a set of points and you are asked to find the inverse of that function. So if the function has a point in the form (x, y) then the inverse function has its points in the form of (y, x). Now when you are given a function f(x) that is in the form of x and asked to find its inverse, equate the function to y. Solve the equation to get the value of variable x in th...

How To: Calculate percentage growth rates in calculus

Want to calculate percentage growth rates (also known as the relative rates of change)? Learn how with this free video calculus lesson, which covers calculating the percentage growth rate using a logarithmic derivative, elasticity of demand and the relation between elasticity of demand and revenue. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever t...

How To: Solve 3 different types of percent problems

In this video the instructor shows how to compute percentage problems. Percentage was first used in ancient Rome when the emperor Augusts levied a 1/100 of a tax on goods sold. To solve percentage problems you need to know how to convert between percentages and decimals. When you have a value in decimal, to convert it into percentage, shift the point two decimals to the right. To convert from percentages to decimals, shift the decimal two places to the left. For example to convert .50 to perc...

Mathematical Beading: Accessories to Thought

Math is unreasonably effective in describing the natural universe. Anyone who's seen Walt Disney's Donald in Mathmagic Land knows this to be so. Well, the axiom works in reverse, too: The physical stuff of the universe can model math right back. And to great effect.

How To: Solve inductive reasoning problems in math

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to solve and work with problems involving inductive reasoning in math.

How To: Do long division in your head

In this video, we learn how to do long division in your head. Start off by trying to do a division problem in your head that divides evenly. This will help you start to get used to doing division in your head. If you come across a problem where you have to carry a number, don't forget to remember it. If you can see a pattern in any division problem, you will be able to solve any problem that you come across. This can be used for small division problems as well as extremely long division probl...

How To: Multiply large numbers

This video demonstrates, without narration, a trick to multiplying large numbers. To do the trick, just draw a diagonal line for every unit in the number and add up the number of times the lines cross.

How To: Find the geometric mean

It doesn’t matter how long ago your last geometry class was, you can still impress your friends by finding a geometric mean. The geometric mean can be used to find the average of numbers with out unusually high or low results effecting the result.

How To: Increase a number by a percentage in basic arithmetic

Need to know how to grow a quantity by a percentage? Learn how. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to increase a number by ...