Hot Math How-Tos
How To: Factor trinomials with the "swing method"
This is a very interesting educational video on how to find the factor trinomials using the swing method. Let us take an example and find the factor trinomials for 2xsquare-13x-45. Let us use the swing method. So now we will get 2xsquare -13x-45. You have to find the suitable factors of 90. It is 18 and 5. If you multiply 18 by 5 you will get 90. You will get (x-18over2)(x+5over2). The final answer is (x-9)(2x+5). Now we have found out the factor trinomials of 2xsquare-13x-45. This swing meth...
How To: Find the equation of a line given 2 points
This tutorial teaches you how to find a mathematical equation of a line given 2 points that exists on the line. The tutorial starts off with 2 points labeled (2,-4) and (3,6). The first step is to determine the slope of the line using the formula given in the tutorial in blue. The slope is then solved as 'm'. Plug the slope and the points into another formula given in green. The tutorial maker provides a tip that one can use x1 and y1 or x2 and y2, however, it must be consistent. After, solve...
How To: Evaluate logarithms using a calculator TI-83
A video to help calculator users find the natural logarithm (log base e, or "ln") and standard logarithm (log base 10, or simply "log") of any number using a TI-83 calculator (works for any issue of the TI-83 calculator or even a TI-84 calculator). Turn on your calculator. To find the natural log of a number, press the "ln" button (the third button from the bottom left), enter the number you want to find the natural log of, press the ")" (closed parenthesis) button, then press enter. The same...
How To: Find the x & y intercepts of rational functions
In this tutorial the instructor shows how to find the x and y intercepts of rational functions. Finding the intercepts of a rational function is similar to finding the intercepts of other normal equations. You can find the x intercept of the equation by setting the value of y to zero and solving the equation. Similarly you can solve the y intercept by setting the value of x to zero and solving the equation. Now while solving this rational function for intercepts if you face a situation where ...
How To: Find a slope of a straight line with: Ax + By + C = 0
In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ...
How To: Find the surface area of a cone without slant height
Math always seems hardest until someone shows you how to do the problem and then it all seems just so simple. This video will walk you through the process of finding the surface area of a cone when you also have to derive the slant height. Use this example to help with your other cone problems.
How To: Calculate Faster Than a Calculator
When you need to crunch numbers quickly — and I mean really quickly — there's a cool method you can use to multiply two numbers together in just a few seconds.
How To: Find the standard deviation with the Z-Score formula
In this tutorial, we learn how to find the standard deviation with the Z-Score formula. First, take your problem and write it out one by one underneath each other. Then, you will need to substitute the numbers in for the variables that are in the problem. Once you do this, you will follow the basic rules of math to find out what the answer to the problem is appropriately. Once you have done this, finish off the problem to find the answer, then you will have found the standard deviation using ...
How To: Figure out the domain & range of a piecewise function
Need to calculate the domain and range of a graphed piecewise 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: Find and sketch the domain of a multivariable function
Looking for a primer on how to find and sketch the domain of a function z = f(x, y) in calculus? Learn how with this free video calc 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: Use a TI-89 to calculate nCr
This video shows you how to do a mathematical representation on computing the nCr function using a TI-89 calculator. You can write the nCr notation in different forms. It can be simplified from nCr to C(n,r). The symbol can either be read "n choose r" or "n taken r at a time" which are from it's probability applications. On the example to find "26 choose 17", go to the Home screen of the TI-89 calculator and then go 2nd 5 which is Math. Go choose probability and then to nCr to type in (26,17)...
How To: Graph half an ellipse
If you are given an equation of ellipse in the form of a function whose value is a square root, you may need to simplify it to make it look like the equation of an ellipse. Now equate the function to a variable y and perform squaring on both sides to remove the radical. Now simplify the equation and get it in the form of (x*x)/(a*a) + (y*y)/(b*b) = 1 which is the general form of an ellipse. Now you will have the x and y intercepts which are a and b respectively. Using this values graph the eq...
How To: Find the circumference of a circle
Use a simple mathematical formula to find the circumference of a circle. The circumference of a circle can be determined by using the formula 2 times pi times the circle's radius. Pi is equal to 3.14. If a circle's radius is 10 centimeters, first multiply pi times 2. Pi, or 3.14, times 2 is 6.28. The next step then is to multiply 6.28 times the circle's radius. Since the circle's radius is 10 centimeters, multiply it by 6.28. This gives you 60.28. 60.28 inches, then, is the circumference of t...
How To: Derive the basic area of a triangle
In this video tutorial, viewers learn how to solve the area of a triangle. The formula for the area of a triangle is A = ½ x b x h or bh/2. The base of the triangle is always at the bottom; it is the side that the triangle sits on. The height is the length between the base and the highest point of the triangle. Multiply the base and height of a triangle; then divide by two or multiply by half. The measurement unit of the answer should be squared. This video will benefit those viewers who need...
How To: Find the slope from a set of points
To find the slope of a line you must have two points and then you must plug in the two points into the slope formula. The slope formula is m= y2-y1 over x2-x1. If the slope is a fraction be sure to reduce to the lowest. Remember if a number is divided into zero it is zero, if zero is divided into the number it is undefined. A calculator can help one remember this. Horizontal lines have slopes and vertical lines do not. Drawing the lines on a graph can help you see the actual slopes and which ...
How To: Find the area & perimeter of triangles & squares
When you are figuring the area of a square, you only need to know the height and width of the shape. Once you know the height and width, multiply them to get the area of the square. To find the perimeter of the square, add all four sides together. To find the area of a triangle, multiply together two of the sides (not the hypotenuse) and then multiply that figure by 1/2. To find the perimeter of the triangle, add all three sides together.
How To: Multiply simple fractions
Watch this video to learn how to multiply fractions by fractions. First multiply the top numbers together. For example, if you have 3/5 * 4/7, multiply 3 * 4 and put your product on top of the fraction you will get as a product. Next, multiply the bottom numbers together and put them on the bottom of your resulting fraction. Next see if you can reduce your product to simplify it. You could also do the reducing step first by canceling out any common factors in the numerators and denominators o...
How To: Find a missing angle outside of a triangle
For people who are having problems with certain parts of geometry, this video will offer you advice on how to find a missing angle on the outside of a triangle when you are provided with the measurements of the other two angles in the triangle. Since the sum of the angles in a triangle is always 180 degrees, you should first take the sum of the other two angles and then subtract this from 180 in order to find the measurement of the missing angle in the triangle. Next, since there are also 180...
How To: Find a slope of a line parallel/perpendicular to it
This video tells you how to find a slope of a parallel / perpendicular to it. In the equation y = mx + c, m is the slope. To calculate the slope of a line that is parallel to another line, you have to consider the rule m1 = m2 which means slope of the first line m1 is equal to the second line m2, if both the lines are parallel. Take the equation y = 2/3x - 7.2/3 is the slope. According to the rule m1 = 2/3 and so m2 = 2/3.Now to calculate the slope of perpendicular line you have another rule ...
How To: Subtract mixed numbers with borrowing
This video teaches you to subtract mixed numbers with borrowing. Consider 2 mixed numbers. For example 8 and 2/7 and the other 5 and 4/5.You have to subtract 5 and 4/5 from 8 and 2/7. First you have to convert the fractions to their common denominator. To equate the denominators of these two fractions you have to multiply the first denominator with the numerator and the denominator of the second fraction and also multiply the numerator and denominator of the first fraction with the denominato...
How To: Draw a circle with a compass for Geometry
The first thing you have to do is draw a line of the same length as the radius of the circle you want to draw. Then, open the compass the same size as the line length you draw is. Rotate the compass and you will create a circle. Please note that drawing this on a single sheet of paper can be difficult because the paper can move. Also, you can try rotating the paper, instead of the compass.
How To: Multiply Any Number by 11 with a Super Fast Mental Trick
Most of the time, when I’m bored during math class, I play with my calculator to satisfy my boredom. Recently, I've discovered that when multiplying any number by 11, 111, or any number similar to it, that it has a pattern (though I guess everything in math has a pattern). I don't know if this technique is original, because I didn't read anything about this. It's just mere observation. If it’s a tried and true technique, let me know.
How To: Use probability to predict weather
In this video, we learn how to use probability to predict weather. Probability is the chance of something happening. If you want to know what the weather is going to be like, you can look at the weather report and see what each day is going to do throughout the week. Ask yourself what the probability is that the weather will be cloudy, judging from what the current work week weather is. First, figure out how many days there are total and then find out how many are cloudy versus how many are s...
How To: Evaluate factorials with a TI-83 calculator
The factorial of a number n can be defined as the product of all positive integers that are greater than 0 but less than or equal to n.
How To: Find the volume of a swimming pool
In this video, we learn how to find the volume of a swimming pool. To do this, you will first need to find the measurements of all the sides that are on the pool. After this, you will plug in the measurements that you found into the equation to find the volume. This equation is: V=AH, volume= area(height). So, plug in the area and the height to the equation for A and H and then multiply these two together. Once you do this, you will find the answer! Don't forget to label the units on the fina...
How To: Convert numbers in and out of standard form
In this video, we learn how to convert numbers in and out of standard form. Standard form is a useful way of writing down very large numbers and very small numbers. To do this, you will look at the number you have and ignore the zeros that are just at the end. Then, write down the basic numbers. Put a decimal point in this number to make it between one and ten. Now, write down x 10 and put the power for how many places the decimal point moved to get to the new number. This will help you write...
How To: Graph inequalities on a number line
In this video, we learn how to graph inequalities on a number line. Inequalities have a greater than or less than sign instead of an equal signs. Remember that these are no different than figuring out how to graph normal equations. First, you will need to remove the single numbers from each side of the equation. Continue to do math on the equation until you figure out what 'x' is. From here, draw the numbers on your graph and then find the number that 'x' is greater to or less than. Use an op...
How To: Calculate standard deviation with graphing calculator
This video tutorial is in the Education category which will show you how to calculate standard deviation with TI graphing calculator. First you got to enter the data in to the calculator. Go to stat and click on enter. This will edit a list. Now you type in these numbers: 50, 20, 33, 40 and 55. Then press stat and click on enter. This will bring up the 1-var stats page. Press the "2nd" button and L1, because all our data is in L1. Click on enter and you will get all the data that you will nee...
How To: Convert top heavy fractions to mixed numbers
This is a video tutorial in the Education category where you are going to learn how to convert top heavy fractions to mixed numbers. Top heavy fractions are fractions with numerators greater than denominators. Mixed numbers are combination of whole numbers and fractions. To convert 12/5, find out how many 5s are in 12. The answer is 2 and after you remove two 5s from 12, you are left with 2. So, 12/5 is equal to 2 2/5. Similarly, in 10/3, you have three 3s in 10 and you are left with 1. So, 1...
How To: Write equivalent fractions
In this tutorial, we learn how to write equivalent fractions. If you have a negative in front of the fraction, it's the same as writing the negative on the numerator or the denominator. If we would have a negative on the top and on the bottom, this would cancel both out to create a positive, which wouldn't be right. To write the fractions, simplify it. If it's already simplified, you will need to multiply the fraction. After you do this, you will finish the equation and have it written out in...
How To: Solve the six problem solution
Solving 6 math problems using different methods is the idea behind this video. First, you make three rows of numbers vertically from 1-9. All the numbers match across for example, 1 1 1, 2 2 2, 3 3 3, and so on. Each set of numbers creates a mathematical problem who's solution is the number six. These problems require some thinking to solve. The only one that is immediately apparent is 2 2 2=6 which is, of course, 2+2+2=6, (3x3)-3=6, the square root of 4 =2. This done on all three of the four...
How To: Rewrite an addition problem as a multiplication problem 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 unpack and solve problems requiring you to multiply whole numbers.
How To: Solve word problems containing radical equations
See how to unpack and solve a word problem containing radical equations with this free video math lesson from Internet pedagogical superstar Simon Khan. 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 equation for a growth pattern
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 an equation that describse the growth pattern of a sequence of blocks.
How To: Find percentages using a standard calculator
Want to find a percentage of one number relative to another? With a calculator, it's easy. And this free video math lesson will show you how to go about it. 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 vertex formula to find the vertex of a parabola
Looking for a guide on how to find the vertex of a parabola using the vertex formula? Learn how with this free video algebra 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 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: 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...