Hot Math Posts
How To: Find determinants with a TI-83 calculator
Looking for a primer on how to find determinants using a TI-83 graphing calculator? See how it's done with this free video math 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: Apply the Pythagorean theorem
Meet the Pythagorean theorem—an indispensable tool for any budding geometer. The Pythagorean theorem will allow you to measure the hypotenuse or any other side of a right triangle when the length of its other two sides are known. For specific, step-by-step instructions on how to use this useful formula, usually given as a^2+b^2=c^2, where c^2 is equal to the length of the hypotenuse, watch this free video geometry lesson.
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: Use interval notation to express inequalities
Could you use a little help figuring out how to use interval notation to express inequalties? 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 give inequalities in interval nota...
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: Solve equations with the order of operations
In mathematics, the order of operations define the priority in which complex equations are solved. The top priority is your parenthesis, then exponents, followed by multiplication and division, and finally addition and subtraction (PEMDAS). This video tutorial demonstrates the order of operation with various examples and explains the associated methodology. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autod...
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: Simplify complex fractions in algebra
Being circuitous and using ample euphemisms has gotten many a politan elected by the dumb and hated by the knowing. Though embellishing speech is often preferred in jovial presidential debates, mathematicians prefer to cut out the fat and get straight to the point.
How To: Prove a triangle inscribed in a circle is right angled
When a triangle is inserted in a circle in such a way that one of the side of the triangle is diameter of the circle then the triangle is right triangle. To prove this first draw the figure of a circle. Now draw a diameter to it. It can be any line passing through the center of the circle and touching the sides of it. Now making this as the side of a triangle draw two lines from the ends of the diameter to a point on the circle. Now join the center of the circle to the other vertex of the cir...
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: Graph x & y intercepts on a TI-84 Plus calculator
In this video the teacher shows us how to use a TI-84 plus graphing calculator to graph a function, adjust the view window, and determine the values of several types of critical points on the graph such as x-intercept, y-intercept, local maximums, and local minimums. After entering the function in the Y= editor she presses the ZOOM button and selects Z-Standard this adjusts the view window to a range of -10 to 10 on both axis. To find each of the critical points requested the teacher uses the...
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: Solve percent problems
Percent problems, also called as proportion problems, are simple problems where you deal with percentages. Given a percentage problem you may need to identify the percentage, the part or whole quantity from it. You can use the proportion or percent equation to do this. Proportion equations says that the ratio of part to the whole is equal to the ratio of percentage to one hundred. Percent equation says that the product of the percentage in the decimal form and the whole gives you the quantity...
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: 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: 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 a missing coordinate given: coordinate & equation
In this video, the instructor shows how to find an unknown coordinate given the other coordinate of that point and the equation that passes thought the point. A point is said to lie on the graph, if the point can satisfy that equation of the line. To check if a particular point satisfies an equation, all you have to do is substitute the value of the point in that equation and check if it validates the equation. Now, substitute the given point with an unknown coordinate in that equation. If th...
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: 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 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: Simplify algebraic equations w/ the minus-one trick
Just follow a few steps to simplify algebra with the minus one trick. First step is to take two algebraic equations with having numerator and denominator algebraic equations. Second step is to divide the denominator with numerator. For example, it have like -c/c, it gives like answer as -1, but we have another type like (c-a)/(a-c) - to solve these types of steps, like multiply numerator with minus(-), it gives the common the minus and -(a-c)/(a-c), then it gives -1 as a answer.
How To: Figure out and calculate sales tax
Video describing about how to calculate a sales tax price based on purchase price and sales tax percentage. There is one example which is described as below:
How To: Calculate the area of any triangle
This video will show you simply how to calculate the area of any triangle using basic geometry formulas. Since a triangle is basically half of a rectangle, the formula for calculating the area of a triangle is base times height. This video offers some insight and examples provided to you by a teacher about how to apply this formula to various types of triangles, whether they are right triangles, equilateral, isosceles, or another form of triangle. By watching this video, you will be well prep...
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...
How To: Calculate percent composition for chemistry
To calculate percentage composition we will take the example CO2 it stands for Carbon-Di-Oxide. It is the composition of Carbon and Oxygen. We have one carbon and its weight is 12.01 and 2 oxygen. So, we will multiply 2 with 16.00 which is the weight of the oxygen.
How To: Find the midpoint of two points using formula
Find the midpoint of two points using a easy formula. Each coordinate has a x and y. X being the first number and y being the second number. So using the formula of x one plus x two then divide the sum by two. Using the same formula with the y coordinates. After plugging the numbers in the formula add the two x coordinates and divide by two. If you follow the same steps for the y coordinate take the two numbers and you have the midpoint of your two coordinates.
How To: Use rise over run to graph a straight line
In this video the tutor shows how to graph a straight line using the rise over run method. The rise over run trick allows you to graph a straight line as long as you have a starting point and a slope value in the form of a fraction. The first step is to graph the starting point. In the second step he states that the numerator of the slope is rise and the denominator of the slope is run. He says that the rise is vertical and the run is horizontal and shows how do rise and run using those value...
How To: Add 3 fractions with common denominators
In this math tutorial the instructor shows us how to add three fractions with common denominators. He says that it is similar to adding two fractions with common denominator. He tells us first to add all the numbers in the numerator which gives us a new number which is the numerator in our answer and the denominator to our answer is the original common denominator. Now, if the resulting fraction is improper fraction, you will have to convert it into a mixed number. In this video the author sh...