Math How-Tos
How To: Work out the circumference of a circle
Simonc1973 teaches you how to work out the circumference of a circle. You start with a circle and draw a line across the circle. That's called the diameter. You multiply the diameter with Pi, which is 3.141. The video is even more amazing being taught by Harry Chapple, a 4 year old MENSA member, who is a maths child genius. He simply takes the ruler, measures the diameter and then calculates the result of multiplying it by Pi's value. The common value for Pi is 3.14. For very accurate results...
How To: Find the vertex when graphing a quadratic equation
The instructor goes about giving a crash course on finding the vertex of a parabola. This is a very nice review of the subject but not really a complete lesson. The instructor fails to explain many of the symbols and other expressions used. The simple way taught by the instructor is the short cut to finding an otherwise complex problem. The nice thing about this technique is that there are no exceptions to this short cut. This is not what someone should learn if they wish to understand the co...
How To: Do long division problems
In this tutorial the instructor shows how to perform a long division through an example. He gives a simple method where takes the first left most number, with minimum possible digits that can be divided by the divisor, and tries to divide it by the divisor and this gives the quotient. Now he shows how to multiply the quotient with the divisor to get a value which is to be subtracted from the original divided number. Now in the third step he shows how to bring down the next digits and asks to ...
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 the area of various polygons
We can calculate the area of the simple polygons like square, rectangle, triangle, pretty easily. Area of square can be calculated by drawing it on a graph paper, of unit cm length and breadth. Area of a rectangle is length X breadth. Area of a triangle is 1/2bh, half of product of base and height. For a parallelogram , area is the product of base and height. For a trapezoid , it is 1/2(b1+b2)h. For some other extreme polygons, we can calculate the area by making it different simple polygons ...
How To: Find the area of a rhombus easily
Finding the area of a rhombus is something that you will need to know in high school mathematics. In this tutorial, learn a quick and easy way to solve this type of equation in a video made especially for students, by students. This won't take you long to learn, and you will be on your way to an A in no time.
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: Solve the two coins problem
Join Ty Yann and explore a coin puzzle with an unexpected answer. 1. Place a five hundred won coin on the top of another five hundred won coin. Make sure the top coin has the 500 level and showing. 2. Rotate the two coins, like a gear, and think of when the 500 will be straight again. 3. Will it be at quarter, a half, 3/4 or a full turn? Thing of your solution and then try it out. Were you correct?
How To: Solve a rational equation with no solution
This is a very interesting mathematical instructional video on how to find rational equation with no solution. How to solve the equation and check the answer. Let us take the example m over m-3 minus 4 is equal to 3 over m-3. In this equation we get m-4m+12 over m-3 is equal to 3 over m-3. When we simplify it further we get -3m +12 = 3. Or -3m = -9 and m = 3. This video teaches you very clearly how to solve a rational equation with no solution.
How To: Graph an equation in standard form
This video shows you how to graph an equation in standard form. In easy to understand instructions, you will learn how to find the x and y intercepts in order to put those two points on a graph, creating a line. Finding the intercepts is as easy as plugging in zero and solving for either x or y. This creates an ordered pair, which can then be graphed. The points are plotted easily on a Cartesian plane, which completes the problem.
How To: Divide rational expressions containing trinomials
In this video the instructor shows how to divide rational expressions that contain trinomials. A division containing two fractions can always be turned into a multiplication by multiplying the first fraction by the reciprocal of the second fraction. This way any division can be turned into a multiplication problem and solved easily. Now after you convert the division into multiplication factorize the equations. Now you can factorize the equations by splitting the middle term and grouping it 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: Add/subtract rational expressions w/ same denominators
This is about adding and subtracting expressions with the same denominators. Go back to simple arithmetic such as 5/6-2/6. All you do is go right across and 1.)Add or subtract the numerator (5-2). 2.) Keep the denominator. 3.) Change to lowest terms. Use the same general rules. In the problem: 9f+6g/6 - 6g-9f/6, you put the numerator all together so that it reads: 9f +6g - (6g-9f) put parenthesis around the second part so you don't forget to distribute the whole part. The 6g's cancel out and ...
How To: Find the area of a hexagon
In this video you can learn how to find the area of a hexagon. Visualize that the hexagon is made up of six equilateral triangles, with each side of the hexagon as the base for a different triangle. Determine the length of any triangle side by measuring it. Each side should be equal in length to any other side. L will represent this number. Determine the height of any triangle. This can be done by putting one end of your ruler at the halfway point on any side of any triangle and the other end...
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: 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: Find the area of a parallelogram and a triangle
This video shows you how to easily find the area of a parallelogram and the area of a triangle. The first part of the video teaches you how to find the area of a paralellogram. The area of a parallelogram is BxH, where B is the base and H is the height. The height is obtained by drawing a perpendicular line from one corner to the base. The second part of the video teaches you how to find the area of a triangle. The area of a triangle is (BxH)/2, where B is the base and H is the height. That's...
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 the area of a trapezoid with a song
This video illustrates a way to remember how to find the area of a trapezoid using a rap song. The step-by-step song is accompanied by a chalkboard rendering of what the song is describing. The equation used is part of geometry and is a good lesson so that you can easily learn what you are supposed to do. This informative video could be used to teach or to learn how to perform this equation so that it can be properly applied.
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: Solve a system by the elimination method
In this video the instructor shows how to solve a system of equations by elimination method. First you need to know how many possible number of solutions you can get by solving a system of equations. There are three possibilities. In the first case there are two lines with different slopes, so they intersect at a point which is the solution to that system. In second case there can be two lines with same slope but are parallel to each other. In this case the system has no solution. In the thir...
How To: Factor & find zeros of a polynomial
This is the video about how to Factor & find zeros of a polynomial. How did I know that x=1 and x=-1 were roots of the polynomial. Suppose the polynomial has a rational root, let's call it. I will assume that p and q are co prime, i.e., the fraction is reduced to lowest terms. What we will be doing is somewhat similar to "factoring by guessing" of quadratic polynomials. Since is assumed to be a root of P(x), we know that if we multiply both sides by, we obtain: Transfer them to the other side...
How To: Use the Simple Trinomial factoring method
In this video, you will learn how to factor a simple trinomial. You will learn how to recognize a simple trinomial, and how to completely factor the trinomial. Also, it shows you how to factor square variables. The last example in the video explains how to factor out a negative first term. You can't just drop the negative and forget it is there. The instructor teaches you how to remove this negative, then reminds you not to forget to put the negative into your final answer.
How To: Figure out the price of something at a discount
In this tutorial the tutor shows how to work around with discounts. He shows how to find out the price of an item after discount is applied to it. He says that this is a regular situation faced by us when we visit shopping malls etc., Now he says that we need to multiply the original price with the discount percentage and divide it by hundred. This gives us the discount amount. Now he instructs us to subtract this discount amount from the original price to get the final discounted price. He f...
How To: Solve logarithmic equations
In this video the instructor shows how to solve logarithmic equations. To solve a logarithmic equation, the first thing you have to do is try to get one logarithmic term if possible. To subtract two logarithmic terms use the formula Log (a) – Log (b) = Log (a/b). Now to get rid of logs, perform exponentiation of the base. Exponentiation of the base is raising a number to the power of the logarithmic term where the number is the base of the logarithmic term. Here the value turns out to be the ...
How To: Find the area of any triangle using simple equations
The area of a polygon is the number of square units inside that polygon. Area is 2-dimensional like a carpet or an area rug. A triangle is a three-sided polygon. We will look at several types of triangles in this lesson. To find the area of a triangle, multiply the base by the height, and then divide by 2. The division by 2 comes from the fact that a parallelogram can be divided into 2 triangles. For example, in the diagram to the left, the area of each triangle is equal to one-half the area ...
How To: Match quadratic functions
This is the demo showing how match quadratic equations in the graphs. Plug in x=0. So everything with x cannot disappear. There is only one negative three in the equations. Let's look at the equations that has the four as y in the set. One of the difference between each equations are the negative in front of the x square and not in the second one. B is the set which opens down and C is the set which opens. Now lets look zero as y on each set. Both of them are opened. Let's look at X intercepts.
How To: Find the volume of a cube
For people who are learning geometry, this video will show you how to simply find the volume of a cube. This video provides the formula as well as some basic examples in order to get you started in finding the volume. The formula for the volume of a cube is the length of one side of a square^3. This is easy to remember since you are making a cube and all sides should be equal in length. By following the simple steps and by watching this video, you should be able to easily find the volume of a...
How To: Solve linear inequalities
In this video you can learn how to solve linear inequalities. Understand the basics of inequalities and linear equations. In an inequality, we say that that one number is greater than (>) another number or less than (<) another. On occasion we say that something is greater than or equal to, or less than or equal to. In a basic linear equation, we solve for the variable of x by subtracting the value from the opposite side or the = sign. Start by writing your equation on a sheet of paper. It wi...
How To: Find the perimeter & area of a rectangle
This video starts out with a basic view of a rectangle and its dimensions. The base is 7 inches while the sides are 4 inches. It then displays the formula for finding the perimeter of the rectangle which is the addition of both bases and both sides. After the substitution of the values into the formula you can quickly come up with the perimeter. Then moving on the area, the formula is the base multiplied by the side. In this case, the base being 7 inches and the side being 4 inches you come o...
How To: Find the opposite and absolute value of a number
View the absolute value of a number as its distance from zero. When you take the absolute value of a number, you always end up with a positive number (or zero). Whether the input was positive or negative (or zero), the output is always positive (or zero). For instance, | 3 | = 3, and | _3 | = 3 also. This property that both the positive and the negative become positive makes solving absolute-value equations a little tricky. But once you learn the "trick", they're not so bad. Let's start with ...
How To: Evaluate square roots
This is the video about how to evaluate square roots. The square root of a number is a number that you can square to get it, that is, a number that you can multiply by itself to get the number. So, 2 is a square root of 4, because 2 x 2 = 4, and 3 is a square root of 9, because 3 x 2 = 9. (-2) x 2 is also 4 and (-3) x 2 is also 9. Numbers that have square roots always have two, a positive one and a negative one, but the square root symbol means only the positive one, so we can have one answer...
How To: Complete Fahrenheit to Celsius conversion
This video shows you how to convert temperatures from Fahrenheit(F) to Celsius(C). In the video, the example of 75 degrees F is used. The formula for converting Fahrenheit to Celsius is given by temperature in Celsius= (temperature in Fahrenheit- 32)/1.8. So for 75 degrees F we take 75 in place of temperature in Fahrenheit. Therefore the equation becomes (75-32)/1.8=C . Further 43/1.8=c and finally C= 24. Hence 75 degrees Fahrenheit= 24 degrees Celsius . This conversion is used as Celsius is ...
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: Understand arithmetic basics to do long division
This video shows us how to understand the basic arithmetic for doing long division. Whenever you are about to perform the division operation, the number which is to be divided is called as the dividend and the number which divides the dividend is called as divisor. So while performing a very long division, usually the dividend is put under a bar and the divisor is put upfront. So while dividing the dividend, the divisor is made to check whether it can divide the numbers involved in the divide...
How To: Test for symmetry algebraically
This video teaches you how to test for symmetry algebraically. You will need to know the basic formats of graphs and the (x,y) setup. Once you get your equation of the line, you will need to replace y with negative y and x with negative x and solve the equation. You will need to solve for x and also for y for the odd and even. If the equations do not equal each other then they are not even or they are not odd. If this is the case then the lines are not symmetrical and that is how you test for...
How To: Use the substitution method to solve problems
This video teaches you how to use substitution to find the point on a graph (the x and y coordinates) where two separate equations would cross. Substitution is a trick of algebra that allows you to find this point without making a graph. The first step is to isolate one of the variables (x or y) in one of the equations. That way, you know that that variable is equal to everything on the other side of the equals sign from it. You can then take that whole side, and substitute it into the other ...
How To: Find the area of a rhombus
In this video the tutor shows how to calculate the area of a rhombus. He gives the formula for the area of a rhombus as area a = ( D * d ) / 2 where D is the length of the longer diagonal and d is the length of the shorter diagonal. He shows how to solve such problems by taking an example of rhombus with lengths of longer and shorted diagonal and computes its area by substituting the values in the area formula. This video shows how to compute the area of a rhombus when the lengths of its long...
How To: Calculate the area of a trapezoid
Finding the area of a trapezoid is essential to high school and college mathematics. In this tutorial, learn how to find the area fast and easily. You will be aceing math tests in no time with this simple guide designed especially for students.
How To: Factor a trinomial, find the GCF, then group
This lesson describes the method to find the factors of a trinomial, which consists of three terms, by grouping. First of all, factor out the greatest common factor (GCF), and write the reduced trinomial in parentheses. Let the terms of the trinomial be written in order of exponent of the variable. For example, 3(3X2+2X-8) trinomial is written in the order of variable, with 3(GCF) factored out. Now identify the coefficient of the first and last terms, for example in this case, it is 3 and 8. ...