Hot Math How-Tos
How To: Factor quadratic expressions using trial and error
Sometimes there's no better way to factor a quadratic equation than by simple brute-force trial and error. Watch this free video algebra lesson to see how it's done. 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: Add, subtract, multiply & simplify polynomials
Could you use a little help figuring out how to work with polynomials in algebra? Watch 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). With this free math tutorial, you'll learn how to subtract, multiply and reduce polynomials in a...
How To: Find the formula for a piecewise function from a graph
Need to know how to find the formula for a piecewise function from a graph? 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 eigenvectors and eigenspaces of a 2x2 matrix
Need help figuring out how to find eigenvectors and spaces for 2x2 matrices in linear 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 see...
How To: Apply the distributive property in math
To solve simple algebraic expressions you have to use different properties. Distributive property is one among them. To apply distributive property in a algebraic expression multiply each term inside the parenthesis by the outside term. In this way you are distributing the outside term to all the inside terms and removing the parenthesis. Hence it is called distributive property. After multiplying add the like terms to simplify it further. Care should be taken to ensure the proper sign change...
How To: Properly read a decimal number
Decimal numbers are numbers which contain a integral part before a point and a decimal part after the point. The first step in solving decimal arithmetic is being able to understand decimal numbers. Reading a decimal number is similar to reading a whole number except for a few minor differences. In a normal number the right most digit is ones place and the place next to it is tens place and so on the value of the position increases as you move left. But a decimal number starts from a tenths p...
How To: Use a protractor to make a pie chart
If you have a circular or semicircular protractor like the one used in this video, making a pie chart is as easy as – well — pie. This will teach you how to use your protractor to measure out each individual slice in your pie chart. Learn how to visualize statistical data through hand-drawn pie charts with this free video math lesson.
How To: Find the length of a segment using the midpoint II
First of all in the given question you have to write down the values of the total length of the line segment, PS=15. The length of the line segment, QR =3. Now you have to find the value of line segment RS. Because you know that the Q is the midpoint of the line segments PQ and QS must be equal. Therefore you can find out the length of the half of the segment using the midpoint. Subtract the value of QR from QS. Given that segment PS=15 and Q is the midpoint, you can conclude segment PQ=7.5 a...
How To: Find the average value of a function over an interval
When you have to find the average of two or five numbers then you have to add all the numbers and then divide then by two or five respectively. However in the case of the function you have infinite many values over any interval. But it is not possible to add all and then divide by infinity. Therefore you have to calculate in a different way. Imagine that you have to find the average of y=f(x). Then you have to average it from the interval from ‘a’ to ‘b’. The inner area under the curve shall ...
How To: Cancel out in basic algebra
This video gives you brief tutorial on simplifying expressions, or canceling out common factors. He starts out by answering the question "What is canceling?" and demonstrates a basic example. You find the greatest common factor between the numerator and denominator, which you then divide both by. This can also be done if you have variables in your fraction. He then shows it can be done the same way if you have binomials in your fractions. However, you must be careful that the denominator does...
How To: Work out the area of a triangle and a parallelogram
This tutorial describes the method to calculate the area of a triangle and a parallelogram To calculate the area of a triangle:
How To: Calculate azimuth in trigonometry
Azimuth is simply the angle of an object in the sky along the horizon. Yes, it's spherical trigonometry but it's not difficult! Check out this video and in just a few minutes you will be able to solve azimuth problems on your own.
How To: Find least common multiple in rational expressions
This series walks you through the steps of finding the least common multiple in rational expressions. This excellent video shows you a clean board, with the instructors voice showing exactly what to do. Don't fret, any question you may have, will be answered. Watching this video will make you feel like your back in the classroom but rather comfortably from your home.
How To: Add and subtract rational expressions
This series walks you through the steps of adding and subtracting rational expressions. This excellent video shows you a clean board, with the instructors voice showing exactly what to do. Don't fret, any question you may have, will be answered. Watching this video will make you feel like your back in the classroom but rather comfortably from your home.
How To: Solve closed line integrals on conservative fields
This three part video walks you through the steps of solving closed line integrals on conservative fields. This excellent video shows you a clean blackboard, with the instructors voice showing exactly what to do. Don't fret, any question you may have, will be answered. Watching this video will make you feel like your back in the classroom but rather comfortably from your home.
How To: Simplify radicals before adding or subtracting
This video in the Education category will show you how to simplify radicals before adding or subtracting. By doing this you will find all like radicals which will then ensure that you have all radicals in the simplest form. Let’s say you want to subtract square root of 45 from 3 square roots of 20. Now square root of 45 can be written as square root of 9 x square root of 5. Because, 9 and 5 are factors of 45. Similarly, 3 square roots of 20 can be simplified to 3 x square root of 4 x square r...
How To: Graph linear equations using y=mx+b
This video is an instructional guide about Graph Linear Equations presented in algebraic form. It is an easy to follow, step by step guide to solving such equations using the graph intercept formula. The first example equation is Y = 2x -1 over y = mx + b. The video then shows you how to breakdown the equation into manageable sums using fractions to represent the data, and then presents the formula for interpreting the answer from these sums onto the graph co-ordinates. The second and third e...
How To: Find the area of a circle when you know the diameter
In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...
How To: Find the volume of a sphere with radius r
Are you slightly rusty on your math skills? This video demonstrates how to find the volume of a sphere with a given radius. The first step is to sketch a solid and cross-sectional view of your sphere to get an understanding of the process to come. Next, find a formula for the area of this cross-section. Third, find the limits of integration. This will allow you to take the area of each cross-section in the sphere, not just the singular one you are viewing. Lastly, integrate this formula from ...
How To: Convert from cubic yards to cubic feet and inches
brettman6533 teaches you how to convert from cubic yards to cubic feet and inches. The volume of a cube is side cubed. If the side of a cube is 1 foot, then the volume would be 1 foot squared. Knowing that a foot equals 12 inches, you transform that into 1 times 12 in times 12 in times 12, which equals 1728 inches squared. If you want to convert a cubic yard, you have to remember 1 yard equals 3 feet. So now 1 yard squared is 1 times 3 feet times 3 feet times 3 feet, which is 27 feet squared....
How To: Solve the circumference of a circle using a cookie
In this video the instructor shows you the diameter, radius and also how to find the circumference of a circle using a cookie as an example. When you draw a line against the cookie passing through its center and touching its boundaries, it is a diameter of the circle. Radius of a circle is half the diameter of the circle. The length of the circle along the border of the circle is called circumference of the circle. The formula to compute the circumference of a circle is 2 * Pi * r, where r is...
How To: Find the area of a triangle with decimal measurements
This is an introductory educational video that shows how to find the area of a triangle with decimal measurements.
How To: Solve percent equations
In this tutorial the instructor shows how to solve percent equations. The general form of a percent equations is that a is b% of c. As there can be three kinds of variables a, b, c, the questions involving percent equations can be of three types having one of the three variables unknown. These kind of percent statements can be solved easily by setting up an equation. So, to convert percent statement into a equation replace the unknown term with n, the 'is' term with equals sign and the '%' si...
How To: Do long division without a calculator
This video shows you step by step how to do long division without the use of a calculator. The video shows viewers two different ways to solve a division problem. It first shows how to do the problem the traditional way, then it shows how to do it according to the long division process. The long division process is where you write the whole division, multiplication, and subtraction process out showing all your work. Long division is mainly used when dividing large numbers. There are three com...
How To: Change Fahrenheit to Celsius
This video is a tutorial on how to convert Celsius to Fahrenheit. The title of the film says it will teach you how to convert Fahrenheit to Celsius, but it does not. It does just the opposite. The video begins by comparing Fahrenheit and Celsius. He points out that Fahrenheit measures water to freeze at 32 and water to boil at 212. Celsius measures water to freeze at 0 and water to boil at 100. To convert Celsius to Fahrenheit, multiply the Celsius temperature by 1.8 and add 32. Many countrie...
How To: Factor a trinomial with negative leading coefficient
In this video the instructor shows how to factor a trinomial with negative leading coefficient. Most of the students are confused when they have to factor a trinomial with a negative leading coefficient. But there are many ways to solve these kind of problems as shown in this video. One way you can do is that take out the greatest common factor (GCF) of -1 from the equation. So pulling the -1 gives you the original trinomial with all the signs of the terms changed. Now go on and factor the ne...
How To: Solve radical equations easily
In this video, the instructor demonstrates how to solve radical equations and inequalities. If you have an equation that contains radicals, re-,arrange the equation so that all the radicals are on one side and the integers are on the other side. To cancel a square root from an equation, square both sides of the equation. The square of the equation cancels out the square root, thereby removing the radical. Even after squaring if you still have a radical left, treat it as a new problem and appl...
How To: Solve equations & inequalities with absolute value
In this tutorial the instructor talks about various strategies for solving equations and inequalities involving absolute value. To do this the first step is to isolate an absolute value. An absolute value is exactly equal to a number. If that number is less than zero then there is no solution. So, if you have an absolute value that is less than a number it means that the real value lies in between negative and positive value of that number. If your number is less than zero then it is empty se...
How To: Find the equation of a circle given: center & tangent
In this video, the instructor shows how to find the equation of a circle given its center point and a tangent line to it. To do this, take a graph and plot the given point and the tangent on that graph. Now, from the center of the circle, measure the perpendicular distance to the tangent line. This gives us the radius of the circle. Using the center point and the radius, you can find the equation of the circle using the general circle formula (x-h)*(x-h) + (y-k)*(y-k) = r*r, where (h,k) is th...
How To: Compare exponential expressions
In this video the tutor shows how to compare exponential expressions and judge if they are equivalent. He shows how to do this using examples to simply exponential expressions. Now after simplifying the numerator and denominator separately he reduces the fraction to arrive at a simple value. Now using this simple values we can compare them and judge if both their values are equivalent. This video gives a good introduction on how to simplify the exponential expression and how to compare them a...
How To: Find the vertices of a polygon of constraints
In this tutorial the instructor shows how to find the vertices of a polygon of constraints. In any optimization problem after defining your polygon you need to find its vertices. First you will have a set of equations which represents the constraints in your problem. Now you have to find the coordinates of the vertex of it by solving the optimization problem. To do that you have to start with a point and check the lines that are passing through it. Now take those lines and solve them for the ...
How To: Find slant (oblique) asymptotes of rational functions
In this educational video the instructor shows how to find the slant asymptotes of rational functions. Slant or oblique asymptotes occur when the degree of the numerator is exactly one greater than the degree of the denominator of the rational function. The way to find the equation of the slant asymptote from the function is through long division. In this long division you divide the numerator with the denominator by following the long division method as shown in this video. Before dividing i...
How To: Solve & find the least common multiple
This is a mathematical instructional video on how to find the least common multiple. Let us now find the least common multiple for 25, 100, 18. This can be written as 5 square, 2 square multiplied by 5 square, 2 multiplied by 3 square. The highest factor in these numbers are, 5 square, 2 square and square. If you multiply 5 square with 2 square and 3 square you will get the final answer as 900. This is the least common multiple of 25, 100, and 18. This method is explained very clearly in this...
How To: Find the equation of a tangent line
This is the video about how to find the equation of a tangent line. As you may recall, a line which is tangent to a curve at a point a, must have the same slope as the curve. Therefore, the slope of the tangent is m = lim f(a + h) - f(a) h-->0 h Since the slope equation of the tangent line is exactly the same as the derivative definition, an easier way to find the tangent line is to differentiate using the rules on the function f. For example, Find the slope of a line tangent to the function ...
How To: Use a mean and scatter plot for Statistics
Wondering how to use a mean and scatter plot for statistics? Just follow the few simple steps as below.
How To: Solve multi-step equations with absolute values
This educational math video describes the steps necessary to solve an equation involving absolute values. "Absolute value" refers to the magnitude of a quantity and is always expressed as a positive number. You can think of absolute value as the distance a number would be from zero if plotted on a number line. Positive 17 and negative 17 both have the same absolute value because both are 17 units from zero on a number line. Because of this, all absolute value problems have two answers, one wh...
How To: Use the Grouping factoring method
This video is about using the grouping factoring method. We're using a four term polynomial. There is a even number of terms. We can break them into two groups of 2. The first group of "2" the common factor is "a." The last group, the common factor is "-2b". The reason we use -2b is to assure that what is in the first group is the same as the second group. Because of the distributive property of multiplication over addition, we take the a-2b and put it in one bracket. Multiply by 3x+1. With 6...
How To: Graph an equation in point-slope form
This video tells you how to draft an equation in point-slope form. Consider the equation (y+4) = 2(x+7) for example. The formula for the point-slope form is (y-y1) = m(x-x1). To plot the graph you have to identify m the slope, the x intercept x1 and the y intercept y1. In this equation the slope is 2 and (x1,y1). The x intercept according to the formula is -x1 but the given value is +7 so you have to figure out what will give you +7,only -(-7) can give you +7 so the point is -7 and now the y ...
How To: Graph by using an X-Y table
In this video the author shows how to graph using an X-Y table. He shows how to do this with a sample equation. He builds a table of x, y values where he takes sample values for x like -1, 0, 1 and now he substitutes these values in the equation of the line and obtains the corresponding y values. Now finally he has an x, y value table which now he shows how to plot it on a coordinate plane. He plots all the three pairs on the graph and connects them with a line finally obtaining the resultant...
How To: Subtract fractions with borrowing
This how-to video describes how to subtract fractions using the borrowing method. The video shows viewers everything they need to know including basic subtraction of fractions, how to find common denominators, to the more difficult borrowing techniques. The narrator in this video does a great job of keeping things simple enough for anybody to understand. At the same time, he goes in depth enough that you really get how to use this technique. The voice in this video is very calm and clear. Thi...