How To: Multiply & Divide Numbers (Basic Elementary Math)

Adding and subtracting may be the easiest of mathematical operations, but once you get it down, multiplication and division can be just as easy. That's why it's called elementary arithmetic. If it were harder, it would be called college algebra or trigonometry. But it's not— it's basic math, and once you get your head around the numbers, you'll never hate math class again! (Okay, maybe you will.)

How To: Find the perimeter & area of a complex figure

In this video tutorial the author shows how to find the perimeter and area of a complex figure. He shows that a complex figure can be subdivided into standard geometric figures. In the current example he divides the complex figure into a rectangle and a triangle. Now he computes the perimeter by adding the three sides of the rectangle and the two sides of the triangle. Similarly he computes the individual areas of the rectangle and the triangle and finally adds then up to find the area of the...

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: Find the percentage of a number

In this tutorial the author explains of how to compute percentages of a given number. He explains that x percent of some number y is x multiplied by y and divided by 100. He says that of means multiply and percentage means for hundred. He goes on and explains this concept with numerous examples. He suggests a small trick to move the decimal point of a number two digits to the left to get it divided by hundred. The author demonstrates many more similar tricks and short cuts using which one can...

Use the quadratic equation: finding the mirror point

In this video the tutor shows how to find the mirror point using a quadratic equation. He says that to graph a parabola you need to find the mirror point symmetrical to the Y-intercept. Now he explains how to find a mirror point using an example with sample values. He begins with saying that the Y-coordinate of the mirror point is same as the Y-coordinate of the Y-intercept. Now you have to find the x coordinate of the mirror point which he shows that it is double the x-coordinate of the vert...

How To: Find X-bar with the Z-score formula

In this video tutorial it shows you how to find the x-bar by using the Z-score formula. In the beginning of this video the formula is displayed on the right, while the values that you need to plug in are on the left. Once you plug in the values and do the cross multiplying, all you have to do is get x-bar by itself on one side of the equation. This is a simple problem on using the z-score formula to find x-bar, it can help you solve more complex problems in the future.

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: Determine if you have a function

In this tutorial, we learn how to determine if you have a function. You will start off with two functions and their points. The 'x' values make up the domain of the function and the 'y' values make up the range. The input values are the domain and the output are the range. If you're checking to see if you have a function, you will need one 'y' for every 'x'. This means that each value has another one that goes with it. Each of the points need to have one partner with them, no more and no less...

How To: Use ">" (greater than) and "<" (less than) symbols

In this video the author explains how to identify the less than (<) and greater than (>) symbols and when to use them. She explains to us to relate the numbers to animals stating that the smaller numbers are smaller animals and bigger numbers are bigger animals. Now she tells us to imagine that smaller animals are eaten up by the larger animals. So she shows a smaller number comes on the left side of '<' sign and bigger number comes on the right side of '<' sign stating that the bigger number...

How To: Simplify a quadratic formula result

In this video the tutor shows how to simplify a quadratic formula result. You can solve a quadratic equation using the quadratic formula. The first thing you have to do when given the quadratic equation is bring all the terms to one side so that you have a zero on the other side of the equals to sign. Now the formula to calculate the roots of the quadratic equation ax*x + bx + c = 0 is x = (-b + root of(b*b - 4*a*c) ) / 2 * a. The other root can be obtained by using the minus sign before the ...

How To: Find extra points for a parabola (quadractic equation)

This is a mathematical educational video on how to find extra points for a parabola. In the first two examples there is no need for finding extra points as they have five points and have zeros of the parabola. In example 3 we need to find extra points. The equation is y=4xsquare-4x+4. You can take x= -1 and get the value for y. You will get a point now. Similarly you can substitute -2 for x in the same equation and get the value for y. Now you get another point. Now you can draw the parabola.

How To: Solve quadratic equation word problems in algebra

Need help figuring out how to unpack and solve word problems involving quadratic equations? 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 a number given Its percent

This how-to video is about how to find a number when its percent is given. This video is really helpful and effective in finding the number when the percent is given, the following steps are explained in the video to find the number when its percent is given:

How To: Write a slope-intercept equation given an X-Y table

In this tutorial the author shows how to derive a slope-intercept equation of a line given an X-Y table. He explains that the general form of slope intercept form which is y = m*x + b. Now he intends to find value of slope, i.e. m first. Now slope is change in y over change in x. He computes the slope using the X-Y values from the table. Next he substitutes a pair of x, y value in the equation to compute the value of y intercept b. Now finally substituting the values in the equation the slop-...

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: 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: 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 surface area and volume of a sphere

In this how to video, you will learn how to find the volume of a sphere and surface area. Let's say you need to find the volume of a sphere with a surface area of 200 cm cubed. You will need to know the formulas for surface area and volume of a sphere. The formula for surface area is 4 pi r squared. The formula for volume is 4/3 pi r cubed. Plug in the surface area of 200 cm cubed and plug it into the formula. You should get an answer of about 3.99 cm. Now you just have to solve for the radiu...

How To: Turn multiplication into sum

This is a handy math trick that show you how to turn a multiplication problem into a sum problem. An unusual way to perform a multiplication. You only need to be able to sum, halve and double numbers. It is not efficient, but it is rather intriguing and fun.

How To: Interpret a standard deviation

A rough definition of standard deviation is that it is a measure of expressing the observed variations about the average in statistical data i.e. by how much do the observed values vary from the mean. This video continues from the previous solved example and demonstrates the mathematical interpretation of the standard deviation that was calculated. We begin with stating the mean and standard deviation values and then calculating the upper and lower bounds of the data based on the standard dev...

How To: Use natural log to solve an exponential function

Looking for a primer on how to use the natural log, e, to solve an exponential 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: Write the equation of a circle in standard form

Here you'll be shown how to take the equation of a circle, and convert it into standard form. Also, it will be explained just what standard form is, while running through the process of conversion. You'll be able to use techniques to quickly work off the numbers on the equation, one by one, until it's simplified enough to understand. Complicated algebra functions become much simpler when you see these easy to use techniques, that will help you rearrange the equation into a form that is actual...

How To: Calculate percentages by example

In this tutorial the author explains of how to find percentages using examples. He explains that x percent of some number y is x multiplied by y and divided by 100. He goes on and explains this concept with numerous examples. He suggests a short cut to movie the decimal point of a number two digits to the left to divide that number by 100. The author demonstrates many more similar tricks and short cuts using which one can easily solve percentage problems. So if you are looking for a good tuto...

How To: Subtract with borrowing

For people who are learning basic math skills, this video will show you how to subtract larger numbers which involve borrowing. If the top number on your rightmost digit is smaller than the number before it, you will need to borrow from the column before it. To do this, you will have to cross out the left hand number, subtracting one from its value. You can then add 10 to your original number and continue with your subtraction. If the left hand number is 0 and too small to be borrow from, you...

How To: Find standard deviation

In this video tutorial, viewers learn how to calculate the standard deviation of a data set. The standard deviation of a statistical population, a data set, or a probability distribution is the square root of its variance. To calculate the standard deviation, users will need to follow these steps. 1) Find the mean of the data. 2) Subtract the mean from each data point. 3) Square each of the values you got in step 2. 4) Then find the mean of the values you get from step 3. 5) Finally, square r...

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: Find the slope of a line given 2 points with fractions

In this video tutorial the instructor shows how to find the slope of a line given two points with fractional values. To do this first name your two points as point 1 with coordinates as x1, y1 and point 2 with coordinates x2, y2. Then substitute the values in the equation of the slope which is slope m = (y2 - y1) / (x2 - x1). Now all you have to do is simply the fraction after substituting the point values. Be careful about the signs while substituting in the formula. Now finally after solvin...

How To: Use and find x & y-intercepts in algebra

A straight line can be represented in the form of a liner equation containing two variables x and y. When the equation is graphed on a pair of coordinate axes, the line passes cut through the axes in two points. The point where the line cuts the x-axes is called as its x coordinate and the point where the line cuts the y-axes is called as its y coordinate. In this way a line has x-intercept and y-intercept. The x-intercept of a line lies on x axes and is in the form (a,0). Similarly the y-int...

How To: Find the area of an oblique triangle using formulas

In this tutorial the instructor shows how to find the area of an oblique triangle using different formulas. To find the area of an oblique triangle there are different formulae. The first formula to calculate the area of a triangle is area A = (1/2) * a * b * Sin(C), where a and b are the lengths of the two sides of the triangle and C is the value of the angle of the triangle that lies in between the two sides a, b. Now substitute these values in the given formula to find the area if you have...

How To: Write a sum/difference of logarithms as a logarithm

To write the sum or difference of logarithms as a single logarithm, you will need to learn a few rules. The rules are ln AB = ln A + ln B. This is the addition rule. The multiplication rule of logarithm states that ln A/b = ln A - ln B. The third rule of logarithms that deals with exponents states that ln (M power r) = r * ln M. Using these three rules you can simplify any expression that involves logarithms to arrive at a single logarithm. The instructor shows how to apply these rules to a f...

How To: Find the equation of an ellipse given a graph

Notes College Algebra teaches you how to find the equation of an ellipse given a graph. You first want to find out the center of the ellipse, which in the video is (2, -3). The major axis is parallel to the X axis. The equation is (x - h) squared/a squared plus (y - k) squared/a squared equals 1. A is the distance from the center to either of the vertices, which is 5 over here. B is the distance from the center to the top or bottom of the ellipse, which is 3. You then use these values to find...

How To: Find the horizontal asymptotes of rational functions

Finding horizontal asymptotes is very easy! Not all rational functions have horizontal asymptotes. the function must satisfy one of two conditions dependent upon the degree (highest exponent) of the numerator and denominator. If the degree of the numerator is equal to the degree of the denominator, then the horizontal asymptote is y= the ratio of the leading coefficients. If the degree of the denominator is greater than the degree of the numerator then y= 0. If the degree of the denominator i...

How To: Add fractions with unlike denominators

In order to add fractions that are not alike, you will need to find the lowest common denominator. This is the least common multiple of the fractions. To add 2/3 plus 1/5, you will need to find the lowest common denominator. Here, it is best to think of all of the multiples of the denominators. If it helps, make a list. For 3, it is 3, 6, 9, 12, 15, etc. For five, the multiples are 5, 15, 20, 25, etc.

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: 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...

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