# Hot Math Posts

### How To: Find the area of complex figures

In this tutorial the author explains how to compute the area of a complex figure. Now he first defines what a complex figure is by saying that a complex figure is a figure made up of two or more basic shapes. He uses an example to convey his idea and breaks that sample figure into basic squares and rectangles. Now he computes the areas of these individual units separately and finally puts them together to arrive at the final area of the complex figure. If you are looking to compute the area o...

### How To: Calculate the area of a rhombus

This is how to calculate the area of a rhombus. A rhombus is a quadrilateral shape in which all sides are congruent. A rhombus has two sets of parallel lines, the diagonals of which form 90-degree angles at the point they meet. Also the angles opposite to one another are congruent. The area of a rhombus can be gotten by multiplying both the diagonals and then dividing the total by 2. Say one of the diagonals is 10 and the other is 12, the area will be 10 x 12 = 120/2 = 60. That is how to calc...

### 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.

### 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: Evaluate exponential expressions in algebra

Need some help figuring out how to solve exponential expressions in algebra? See how it's done 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: Change mixed numbers to improper fractions

In this Math tutorial, you will learn how to convert a mixed number into an improper fraction. The narrator explains the process in a very concise yet simple manner that will make math problems involving mixed numbers so much easier to solve. The general idea is to multiply the whole number with the denominator and then add that to the numerator. The explanation and illustration in the video makes it easy to understand.

### How To: Calculate angles formed between transversals and parallel lines in geometry

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 calculate the value of angles formed between transversals and parallel lines in basic geometry.

### How To: Find the sides of a 30-60-90 right triangle

Does your geometry homework have you stumped about finding the sides of a 30-60-90 right triangle? Have no fear, in this excellent video, Davitily from Math Problem Generator explains the process step by step using easy to follow examples. The video covers common examples and tricky snags that you are likely to encounter on your next math class exam. Stop scratching your head over finding the legs and hypotenuse in your geometry or trigonometry homework by watching this informative video.

### How To: Determine whether a pair of lines are parallel

See how to determine whether a set of lines are parallel given their equations 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). With this installment from Internet pedagogical superstar Salman Khan's series of free math tut...

### How To: Add ounces and pounds together in basic mathematics

Need how to know how to add pounds to ounces and ounces to pounds? 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 sum pound and ounce weight units.

### How To: Solve multivariable linear equations

Looking for instructions on how to solve linear equations with multiple variables and constant terms? Look no further. 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 ma...

### 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 the volume of a regular pyramid

In this video, you will learn how to find the volume of a regular pyramid. Finding this volume is one of the basic steps in high school geometry. This tutorial will show you all of the steps and equations you need to solve this problem and soon you will be heading straight to the top of the class!

### 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: Find patterns in arithmetic sequences

Need some help wrapping your head around linear relationships? See how it's done with this free video math lesson. Need help finding the 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...

### How To: Calculate lateral & total area of a cylinder

Steps involved in calculating the lateral surface and total area are:

### How To: Use the Cosine Law

In this video tutorial the author shows how to use the Cosine Law. He shows how to find an angle of a triangle where he know all the sides of a triangle, using the cosine Law. He uses a lower case letter to designate a side and a capital letter to designate an angel apposite to that side. He gives the formula for the cosine law using a triangle as an example. Now he goes on and demonstrates how to use a scientific calculate. He shows how to use the degree mode in the calculator to solve these...

### How To: Divide small numbers by big numbers

This is a mathematical educational video on how to divide a small number by a larger number. You are aware that it is easy to divide a larger number by a small number. For example, if you want to divide 379 by 9 it is easy to do so. But if you have to divide 9 by 379 it is a bit difficult. You have to add a zero and see if you can divide. You need to add one more zero so that you can divide 900 by 379. But you should know that the answer would start like this 0.0 as we have added 2 zeros alre...

### How To: Calculate the area of a parallelogram

Calculating The Area Of A Parallelogram A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is:

### 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: Find a missing side of a triangle, similar to another

In this tutorial the author shows how to find out the missing side of a triangle which is similar to an other triangle. He explains the concept of similar triangle using diagrams and by showing that similar triangles have equal corresponding angles and parallel sides. Now he labels sides of similar triangles and intends to find out the length of unknown side. Now in similar triangles, as the lengths of sides are proportionate he shows how to write a equation of proportion and solve it finding...

### How To: Convert between diameter and radius

To convert between diameter and radius just follow a few steps. Sometimes we aren't given the number directly so first we need to find the diameter.

### How To: Convert Fahrenheit to Celsius with a formula

In order to convert Celsius to Fahrenheit, you will need to use this formula: F = 9/5C + 32. Therefore, you will need to solve for C or substitute values and solve in that manner.

### How To: Solve percentages without a calculator

Want to know how to find percentages quickly without the use of a calculator? It's easy. This free video math lesson will show you 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 study for that next big test).

### How To: Determine the age of a fossil using carbon-14

If you have a fossil, you can tell how old it is by the carbon 14 dating method. This is a formula which helps you to date a fossil by its carbon. If a fossil contains 60% of its original carbon, how old is the fossil? The half life of carbon 14 is 5600 years. That means this is how long it takes for half the nuclei to decay. After 5600 years, if we start with a gram, we end up with half a gram. This rather complex formula shows you how to solve this puzzle using accepted scientific methods.

### 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: Identify characteristics of a sample during a survey

To identify characteristics of a sample in your survey, there are many factors to consider of your samples. The first four characteristics you need to focus on are gender, age, income level, and education level. All four of these characteristics must be proportional to that of the population. You also need to consider the geographic location. Only take samples from the immediate geographical area. Finally, an important characteristic of the survey is the sample size. You do not want to ask to...

### 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: Convert fractions to percents in two steps

This video shows you how to easily convert fractions to percents. You can convert fractions to percents in 2 easy steps. The first step is multiplying the fraction by 100 (e.g.. your fraction is 3/5; 3/5 x 100 = 3/5 x 100/1 = 300/5). The second step is reducing the fraction, when possible (e.g.. 3/5 x 100/1 = 300/5 = 60). Don't forget to add the percent sign (%)(you obtained 60%). That's it! Good Luck!

### How To: Find the Slope Given 2 Ordered Pairs

Slope is the change in Y over the change in X. Written out, the formula looks is as follows: (y2-y1)

### 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 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: Find the coordinate of a point

In this video the author shows how to plot a point on the coordinate plane. He explains about the coordinate plane and shows how to read and write points to it with an example. He says that any point on the coordinate plane has an x, y- coordinate values. He says that for any point its projection on the x-axis is its x-coordinate and the points projection on y-axis is its y-coordinate. He shows how to find this out for a sample value and plots the coordinates of it. In this video the author u...

### How To: Derive the area of a circle

This video is about deriving the area of a circle of radius 'r' using polar co-ordinate. First, we draw a circle and its radius 'r'. Then draw another radius close to it, so that it forms a small triangle-like figure. To find the area of the complete circle, divide the circle into similar small triangles. The area of each triangle is given by half the product of its perpendicular and the base. We give the angle between the two radii as d?. We get the area of the small triangle by substituting...

### 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: 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: Find the formula of a piecewise function given a graph

This video shows how to find the formula of a piecewise function when given a graph. The first step is to write a definition for the graph, which is done by identifying the different domains shown in the graph. The second step is writing formulas for each domain specified by the lines in the graph. The point-slope formula is used to identify the slope and y-intercept for the leftmost domain, which has a sloped line. A point and horizontal line make for simpler equations in the other pieces of...

### How To: Find the value of a variable in an algebraic equation

Need help figuring out how to solve simple 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: Spend Money on a Graphing Calculator? Nah—Just Use This Web-Based TI Emulator

For the majority of my math classes in middle and high school, a graphing calculator was a must. While the calculators were very useful to have, they were quite steep in the price column. After losing the TI-83 graphing calculator my parents bought me in high school, I had to save up my own money to buy the next one.

### How To: Find the equation of a line given 1 point

Need help figuring out how to find the equation of a line given a single point? 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).