# Hot Math Posts

### 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: 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: Bisect a line segment

In this tutorial, we learn how to bisect a line segment. First, you need to adjust your compass so the distance from the sharp part and the drawing part is the size of the line. Then, put the sharp part on one side and draw your arc with the pencil. Do this on both sides of the line so your image shows two arcs that intersect each other. Since you have these two intersecting lines, you can draw a line between these to show where the middle of the line would be. Use a ruler to draw this straig...

### How To: Solve inductive reasoning problems 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 solve and work with problems involving inductive reasoning in math.

### How To: Simplify & solve multi-step equations in algebra

Looking for a primer on how to combine like terms and/or use the distributive property to solve algebraic equations? 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 the Height of a Trapezoid.

Step by step directions for finding the height of a trapezoid. Video: .

### How To: Find the standard error of the mean

In this video the tutor explains about the standard error of the mean. He starts explaining by drawing the diagram of a distribution and now he takes ten samples from the distribution and starts plotting them. He says that in theory if we do it infinite times then we can obtain the sampling distribution of the sampling mean. For the example he takes the number of samples as 10. Now depending on these values of n we can get different sampling distributions. Now he intends to find the mean of t...

### 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.

### 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: Translate a sentence into math symbols

We will be translating the sentence "twice y differs from 5 by more than two, “into a mathematical equation. The word twice generally means two times, so 2*y (because y comes next in the sentence). Differs normally means is different and a difference from something in a mathematical sentence means subtraction most of the time, thus minus five. We don't know if we’re talking about below 5 or above 5 on the number line, so we put absolute value around the equation. More than implies a greater t...

### How To: Solving for "x" using multiplication and division

Solving for "x" using multiplication and divisionHere is a typical algebraic equation "2x=12". Multiplication in algebra will have the "x" next to a number. The process will be a combination of multiplication and division to solve for "x". To get "x" alone, we do the opposite operation. 2x/2=12/2. Bring down the "=". You must balance the equation to make sure you did the computation correctly. 2x6=12. Next, we have a multiplication and addition problem. 4x+7=15. We must get rid of the 7. +7-7...

### How To: Use the vertical line test

This test can be used to determine whether the given graph is a function or not.

### How To: Connect interval notation and compound inequalities

Math is fun! That is a statement that not many people find to be true. But it can be if you understand it and know a few tricks to solving certain problems. In this tutorial, you'll find out how to connect interval notations and compound inequalities. Don't know what those words mean? Check out the tutorial, it may help you with any problems you have. Good luck and enjoy!

### How To: Use the law of tangents in trigonometry

This video explains and provides examples for the law of tangents, a law occasionally used in trigonometry.

### How To: Find points on y-axis a certain distance from a point

This is video on mathematics. It specifically deals with geometry. The video describes how to determine where the y-intersects are when a point and distance to the y-intersect are given. The author starts out by giving an example ordered pair. The speaker next shows an example of how to solve such a problem. The speaker uses the distance formula along with the given distance and x-coordinate in order to solve for the y-intersect values in question. Most of the video entails solving this example.

### 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 surface area of a rectangular prism quickly

Do you need help in math? Unable to calculate the surface area of a rectangular prism? This video helps you understand how to calculate the surface area of a rectangular prism. By showing each step required to calculate the surface area of a prism and a detailed explanation of each step, anyone will be able to learn how to successfully calculate the surface area of a rectangular prism. By the end of the video, you can also calculate the surface area of a rectangular prism.

### How To: Use Green's Theorem to solve a line integral

This three part video walks you through using Green's theorem to solve a line integral. 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: Subtract fractions from a whole number

In order to subtract fractions from whole numbers you have to perform a few steps. First we have to borrow one from the whole number. So if you are subtracting 1/16 from 3, 3 becomes 2. Then you have to change the one you borrowed, so the 1 becomes 16 over 16 or 16/16 to match the common denominator in the fraction 1/16. So 16/16 - 1/16 = 15/16. Then you add the 2 that you had left after you borrowed the one from the whole number. The answer is 3 - 1/16 = 2 15/16.

### How To: Find the Radius of a Circle from Arc Length

The video provides two example problems for finding the radius of a circle given the arc length. Problem one finds the radius given radians, and the second problem uses degrees.

### How To: Add fractions together

In this video, we learn how to add fractions together. First, try doing a simple equation like 1/2 + 1/2. From here, you will simply just add together across the board. Once you get the answer, it will be 2/4, but you must simplify this so it's lower. Check this and do the reverse to make sure it's correct. Do this for all of the fractions that come your way and you will be doing fractions more easily each time! Just make sure you simplify when you reach the end, or the answer will not be cor...

### How To: Find the domains of rational expressions in algebra

Learn how to find the domain of 3 different rational expressions that have quadratic expressions in the denominator 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 study for that next big test).

### How To: Find the domain of a function in precalculus

Looking for a primer on how to find the domain of a function in precalculus? Learn how with this free video precalc 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: 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: Draw an isosceles trapezoid

This is a video tutorial in the Education category where you are going to learn how to draw an isosceles trapezoid. This video demonstrates how to draw an isosceles trapezoid with a long base (B), a short base (b) and a 35 degree angle. First you draw the long base. Now center the short base at the center point of the long base and mark the end points of the short base with dots. Next draw perpendicular dotted lines from the dots extending upwards. Draw 35 degree angles from either end of the...

### How To: Find the polar form of a complex number

Need a little help with your math homework? No problem, the Math Centre offers students video tutorials that will provide as a reference guide for self-study. Students get self-study resources targeted to the needs of individual courses, and teachers gain generic mathematics support and study materials for use with students.

### How To: Perform a quadratic regression with a calculator

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 the partial derivative of a vector-valued function using a calculator to perform...

### How To: Express a ratio as a fraction in simplest form

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. With this installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to rewrite a ratio as a fraction in its simplest form.

### Brain Wash Trick: Guessing Your Phone Number & Age in One Minute

I will guess your phone number and age in one minute.

### 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: Compare 2 distributions with the Z-Score formula

This is a video tutorial in the Education category where you are going to learn how to compare 2 distributions with the Z-Score formula. In this example Doug's class has X bar as 71 and a standard deviation of 4. Corey's class has X bar as 68 and a standard deviation of 11. If both Doug and Corey beat the class average and have the same standard score, will Doug have a lower grade than Corey? If both of them have a standard score of 1.5, then Doug will get 77 marks and Corey will get 84.5 mar...

### How To: Solve rational equations easily

This video revolves around solving rational equations in Algebra 2. When you are given a rational equation, you have to find the greatest common factor and multiply all fractions to get that common factor. If a fraction already has that common factor, then no further step is necessary for that one. Next, you have to multiply all fractions by the greatest common factor to get rid of all denominators. Finally, the remaining equation is simple math and you only need to solve the equation for the...

### 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: Graph a parabola properly in vertex form

This video shows viewers who are interested in mathematics how to graph a parabola whose formula is displayed in vertex form, or the form y=a(x-h)^2+k, where the vertex is (h, k). After determining the vertex, plot it on your graph. After graphing your vertex, your axis of symmetry would be x= h, or the x-coordinate of your vertex. The a value in your equation will act as your slope in this case, and your should graph the two points which correspond to this slope on your plot 1 unit away on e...

### How To: Divide exponents with the quotient rule

Exponent of a number is nothing but the number multiplied to it self the exponent number of times. So five squared it equal to five multiplied to it self. Now when an exponential number is divided with another such number the result is the number raised to the different of the exponents. That is the ratio of x raised by a to x raised by b is x raised to (a-b). Similarly if we multiply a exponential number with other such number, the result is equal to that number raised to the sum of exponent...

### How To: Use the percentile formula in Statistics

In this tutorial the instructor explains the percentile formula. He says that the percentile formula is used to find the percentile rank of a data point in a group of data. He takes an example that consists of the lengths of puppies. Now he intends to find out the percentile rank of any puppy in the group. He shows that the formulate to compute a percentile rank of a particular puppy is rank R = 100 * (N< + (1/2)N= )/ Nt, where N< is the number of puppies whose length is less that the length ...

### 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: Solve linear equations with fractions in algebra

Need help figuring out how to solve a linear equation involving fractions in algebra? 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: 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: Divide numbers with exponents

In this tutorial, we learn how to divide numbers with exponents. The quotient rule states that we can divide two powers with the same base by subtracting the exponents. With the same base, you can subtract the exponents to get something that would be the answer. For example, if you have 6(to the fourth) divided by 6(to the second), this would come to equal 6(to 4-2). This would break down to equal 6(to the second power). Once you have this, you will be able to do the math for this and figure ...