Everything Else — Page 27 of 44 « Math

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: Factor trinomials

In this video, the instructor shows how to factor trinomials. An equation is a trinomial if it has three terms. If you factor a trinomial, you are left with two binomials which are the factors of the original trinomial. Multiplying them would result in the original trinomial. Now factor the last numerical term such that the sum or difference of those factors gives you the numerical coefficient of the middle term. Now split the middle term according to the factors obtained in the previous term...

How To: Understand parallel lines & transversals

This video explains the properties of parallel lines and transversals in geometry. The instructor, Robert Ahdoot, uses an analogy in which he compares lines and transversals to the streets of Manhattan, New York. Continuing with this comparison, he goes over corresponding angles of two parallel lines cut by the same transversal, also explaining when they're equal. He then shows where interior and exterior angles may be found, and then goes over whether two angels are same-side or alternate, d...

How To: Graph a linear equation in 3 different ways

In this video tutorial, viewers learn how to graph a linear equation in 3 different ways. The first way is to use the table of values. It is the slowest method but it always work. It is the most useful. The second way is to use the slope-intercept. It is more faster than the table of values and is very versatile. The third way is to use the intercept-intercept. It is the fastest and easiest method to do. This video will benefit those viewers who are learning about graphing in mathematics and ...

How To: Use probability of dependent events

In this video you will learn how to use probability of dependent events. The video starts with a small advertisement to there website http://www.yourteacher.com. Then its followed up by a math instructor taking you through a example problem to help you understand how you can begin solving problems of your own. The problem used in the example is: Andrea has 4 red socks and 8 blue socks in her drawer, she chooses one sock at random and puts it on, she then chooses another sock without looking, ...

How To: Graph a line using slope intercept form

A basis of algebra, slope intercept form can easily bring your equation to a graph with ease. This video will show you exactly how to graph equations using the slope intercept form.

How To: Add and subtract integers

In this video the instructor teaches how to add and subtract integers. When adding or subtracting two numbers there can be four kind of situations depending on the signs between the numbers. When you are adding two numbers which are both positive then you move forward on the number line adding the two numbers together to give the result. Similarly when adding two negative numbers together then you move left side of the number line. Go to the left by the value of first number and go further le...

How To: Get the radius and area of a circle with circumference

This video from Your Teacher is one of a range of math solutions. (which is the measurement from the center to the edge when drawn in a straight line) and also the area of the circle, is the amount of total space within its perimeter. The circumference of this circle is 20 pi. The circumference is 2 pi r. So 20 pi is 2 pi r. Which factors down to show that 10 is the radius (10=r). The area is pi r squared. As we know the radius is 10, we can work out the area - 100 pi.

How To: Multiply integers together

In this video the instructor shows how to multiply and divide integers. When multiplying or dividing two numbers if the signs of the two numbers are same then the sign of the result is a positive number. When multiplying or dividing two numbers if the signs of the two numbers are not same then the sign of the result is a negative number. So a positive number multiplied by a positive number gives a positive number. Similarly a negative number multiplied by a negative number gives a positive nu...

How To: Solve 3 different types of percent problems

In this video the instructor shows how to compute percentage problems. Percentage was first used in ancient Rome when the emperor Augusts levied a 1/100 of a tax on goods sold. To solve percentage problems you need to know how to convert between percentages and decimals. When you have a value in decimal, to convert it into percentage, shift the point two decimals to the right. To convert from percentages to decimals, shift the decimal two places to the left. For example to convert .50 to perc...

How To: Graph a quadratic function in factored form

This video deals with solving quadratic functions. It does not involve the use of the quadratic equation; rather, only factored equations are used. The speaker starts out with a factored quadratic equation. The speaker goes on to do the mathematical steps necessary to find both the x and y intercepts of the quadratic function at hand. The author then continues on with the example to find the function's minimum. Next all of the points that have been solved for are plotted and the function is s...

How To: Understand integers and the number line

User DayTeacher helps you understand integers and the number line. When numbers were conceived, man had the basic concept of small numbers. The first things you learn in a language are numbers. The weather might have had an impact on numbers, as temperatures dropped below 0. When talking about years Before Christ (BC), you could say 1000 B.C. is actually -1000. Being in debt means negative money. Two days ago is -2 days from the time we are talking about. Integers are positive whole numbers, ...

How To: Factor a trinomial

In this video the instructor shows how to factor a general quadratic polynomial. Here the first step is to identify the coefficient of the squared term. Write the reciprocal of the numerical coefficient of the squared term out side and write two separate parenthesis which are going to contain the binomials which are the factors of the original equation. The first term of both the binomials is the first term numerical coefficient times the unknown variable. Now multiply the first term numerica...

How To: Simplify complex fraction

In this video the instructor shows how to simplify a complex fraction. A complex fraction is a fraction that has fractions in both the numerator and the denominator of the original fraction. Complex fractions can look intimidating but are generally simple to solve, as shown in this video. A fraction is nothing but a division of its numerator and its denominator. So in a complex fraction basically you are dividing two fractions. Now you can turn this division into multiplication by multiplying...

How To: Add consecutive odd numbers

Professor ElvisZap teaches you about adding consecutive odd numbers. You can learn this faster by drawing squares near the numbers themselves. If you are doing 2x2, draw 4 squares. They will be arranged in columns of two. For 9 you will draw 3 columns of 3. 16 are 4 columns of 4. 16 is also 1+3+5+7, which are all odd consecutive numbers. 25 are 5 columns of 5, but also 1+3+5+7+9. If you start counting 1 as the zeros odd number, then 3 as the first odd number, the nth odd number will be (2xN+1).

How To: Factor a trinomial, GCF, then unfoil

In this video the instructor shows how to factor a polynomial. A polynomial having three terms is called as trinomial. Now if you factor it you will obtain two binomials whose product will be the original polynomial. Before factoring a polynomial you need to find out if the polynomial has a GCF. Look out for the common variables in all the three terms and pull them out which is the GCF of the polynomial. This simplifies the original equation to a polynomial which is of lower degree. Now facto...

How To: Solve quadratic equations by factoring

This is a great educational video on how to solve quadratic equations by factoring. Let us take an example and try to learn the method. Here is a quadratic equation: (r+7) (r-9) = 0. Consider zero-factor property. For real a and b, if a.b = 0, then a = 0 or b = 0 or both are equal to zero. So r+7 = 0 or r-9 = 0 > r = -7 or r = 9. Hence, r = -7, 9. Similarly to solve a quadratic equation (13r+7) (6r-18) = 0, we will get 13r = -7 or r = -7 over 13. Also 6r = 18 or r = 3. So r= -7over 13, 3. Thi...

How To: Fill a cone

This is a very interesting instructional video on how to fill a cone. Pour oil into a cone of diameter 30 inches and depth 40 inches. Now find the volume of the oil as a function of its depth. Volume = 1 over 3 phi rsquare h. We don't know the height and depth of the oil poured into the cube. Draw similar right angled triangles. In one right angled triangle the height is 40 inches and in the other triangle it is h. Similarly the height is 40 inches and h respectively. Now rover h =15 over 40....

How To: Stretch, shift & reflect the graph of a square root

Professor ElvisZap teaches you how to stretch shift and reflect the graph of a square root. A square root function is the opposite of a squared function. You start with y=square root of (x-1) it becomes 0<=x-1. then 1 <=x. You use the graph and solve it as you would for any function using small values first, then you have y=square root of x - 1, the domain 0<=x. This shifted the graph down 1 unit. 0=square root of x - 1, 1=square root of x, 1=x. Then the range is [-1 + infinity). Continue in ...

How To: Discover the area of a triangle

Before you can find the area of any geometrical figure, recall what you are finding when you solve for the area. The area is the surface of a 2-dimensional shape. When trying to find the area of a right triangle, the easiest way is to first double the triangle so that it resembles a square. This is particularly important if you don't know the length of the hypotenuse. Using the knowledge that the area of a square is the length multiplied by the height, calculate the area of the square you cre...

How To: Find the area of triangles and other geometric shapes

The video shows us how to find the area of triangles and other geometric shapes. First, before starting to find the areas, we need to know the basics of what do those shapes actually mean and we need a little bit of vocabulary to back us up. First, the parallelograms are four sided figures with two sets of sides which are parallel to each other. The rectangles and the squares qualifies the parallelograms and also the parallelograms except that they have slanted sides and the triangles are thr...

How To: Do long division with remainders

This video goes through the step by step process of doing long division with remainders. Multiple examples are used throughout the video to give the viewer a better idea of how to properly complete the difficult task. Perfect for anyone learning long division for the first time, or for anyone attempting to relearn long division after forgetting how to do the process (an all to common occurrence in a world with calculators on every cell phone).

How To: Multiply binomials with the FOIL method

Multiplying polynomials is a distributive property. If you are given with two binomials and asked to multiply them, you need to apply the distributive property and multiply the terms of binomial with the terms of second binomial. To do this first take a term of first binomial and multiply it with the second complete binomial. Now take the second term of first binomial and multiply it with the second binomial adding or subtracting it from the previous result depending on the sign between the f...

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: Find the area between curves

This video shows how to find areas between curves. The basic idea is that we find the space trapped between two curves on a graph. The formula for finding this is top curve, subtract bottom curve and then integrate. The presenter shows a parabola that goes through the origin. Then he draws a line that runs through the origin. We try to find the area trapped between the two. You take your smallest x co-ordinate to the largest x co-ordinate, you take the curve on top (2x) and subtract the curve...

How To: Find the slope of a line given 2 points

In this video the instructor shows how to find the slope of a line given two points that like on the line. Slope of a line is the measure of the steepness of the line compared to the angle made by the line with the x-axes. A line with positive slope slants forwards and a line with a negative slope slants backwards and a line parallel to x axes has zero slope. So if you are given two points (x1, y1) and (x2, y2), the slope of the line passing through those two points is equal to m = (y2 - y1)/...

How To: Simplify complex fraction w/ single fraction on bottom

This is a great instructional video on education. This educational video teaches you how to simplify a complex fraction with a single fraction on bottom. Let us learn this with an example. Let us assume we have to simplify the complex fraction 5 by x-4 divided by 5-4x by 5. When you simplify this you will get 5-4x over x divided by 5-4x over 5. You will now get 5-4x over x multiplied by 5 over 5-4x. This is equal to 5 over x. This is how we have to simplify a complex fraction with a single fr...

How To: Understand the Pythagorean Theorem

In this video Ken teaches you about the Pythagorean Theorem. The Pythagorean Theorem is used to find the missing length of a side of a right triangle. By watching this video, you will learn how to find any the length of any side by using a simple mathematical formula. Ken walks you through various examples changing the dimensions of the triangle you are solving as well as changing the side you are solving. Ken even includes a real world application to further your understanding of the Pythago...

How To: Multiply and divide three rational expressions

In this video, the instructor shows how to multiply and divide rational expressions. To solve a rational expression that contains many terms, solve step by step by following the order of operations. Order of operations advises one to work the parenthesis part first; so solve the equation inside the parenthesis first. If you have a fraction multiplied by another fraction, first factorize the numerator and denominator of both the fractions. Cancel out any common factors simplifying it. In case ...

How To: Find the area of a circle with pi

This video shows how to find the area of a circle using a formula. The formula for area of circle is pie multiplied by square of radius. Pie is actually an infinite number but for the sake of convenience we consider the value of pie as 3.14. So we multiply the square of radius with 3.14. Radius is the distance between the center point of the circle to any of the outside arcs. It is actually half of the diameter (diameter is the distance between two arcs of a circle). As an example here the ra...

How To: Solve quadratic equations by square root method

In this video the instructor shows how to solve quadratic equation by the square root method. The square root property of equations states that if k is positive and a*a = k, then a is equal to square root of k or -1 times the square root of k. So to solve a quadratic equation by square root property first get the equation in the form of a*a = k. Now apply the square root property explained in the previous step to get the result. The instructor now demonstrates these concepts by solving some e...

How To: Solve equations with fractions and decimals

In this tutorial the instructor shows how to solve equations with fractions and decimals. When you have a fraction first try to simplify it by canceling out the common factors in the numerator and the denominator. If there are any decimals convert them into fractions. Now if you have a number multiplying a equation apply distributive law and simplify the equation. Now finally try to get the variables on one side and numerical terms on the other side of the equation and finally solve for the u...

How To: Use geometry nets

Viewers learn that a net is the shape formed by "unfolding" a 3-dimensional figure, so a net shows all the faces that make up the surface area of the figure. Viewers are then asked to determine what type of 3-dimensional figure can be made from a given net (note that a cylinder has 2 circular bases, a pyramid has triangular faces, a cone has 1 circular base, and a prism has rectangular faces). Students are also asked to determine if a given net can be used to make a cube. This video will bene...

How To: Graph compounds sentences with the word "or" in hem

A Teacher shows us how to graph compound sentences with the word "or" in them. These graphs will have arrows pointing out in different directions. On the number line draw arrows from the numbers in your compound sentence. So for example if after solving a problem with inequalities the problem has two possible answers that it could be, you would record both of the answers that it could possibly be. For our example we will use x is greater than seven, and x is less than three. You would then dr...

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: Understand parallelograms

This video helps us understand parallelograms and its properties. The video starts with the description of the basic properties of a parallelogram. The parallelogram is a four sided shape which has the sum of all four interior angles equal to 360 degrees. The opposite sides of a parallelogram are equal and parallel. Then the video talks about the angles in the parallelogram. The parallelogram has a lot of symmetry. This makes the opposite angles of a parallelogram equal. The same side angles ...

How To: Find the percent change using proportions

In this video, the instructor shows how to identify the percentage change using proportions. When a given quantity increases or decreases by certain amount then we can calculate the percentage change in the quantity, which can be either increase or decrease based on the new value of the quantity. To solve these kind of situations you should know that the ratio of amount of increase (or decrease) of an amount to its original amount is equal to the ratio of percentage increase (or decrease) to ...