### How To: Find the formula of a given sequence

In this tutorial, we learn how to find the formula of a given sequence. First, you need to decide what you're starting with. Start with a1, then continue on with a2, a3, and a4. Eventually, you will have an "An". You will have an "n" in your numerator and the denominator will start between the numbers of your fractions. Look to see if that works, then you have to see where the signs alternate on the fractions. Write in any negatives that you have, then figure your power out. Once you follow t...

### How To: Write a logarithm as a sum or difference of logarithms

This video shows the method to write a logarithm as a sum or difference of logarithms. The square root of the term given is taken out as half according to the rule. Then the numerator and denominator is divided into product of factors. This is broken into the difference of numerator and denominator according to the rule. Finally, the product of factors is expressed as the sum of factors. Now we see the domain of the term. As the term is a square root of the term it should be greater than zero...

### How To: Remember "greater than" & "less than" symbols

This video shows you how to easily remember "greater than" and "less than" math symbols. The first thing you have to remember is that "less than" symbol looks like the letter L ("less than" symbol is "<"). When you see this sign, remember that < looks like L and means "less than". The other symbol, "greater than" does not look like the letter L, therefore it cannot be "less than" and it's easier to remember. The "greater than" symbol is ">". That's it! Good Luck!

### How To: Find the Percent Given Two Numbers

Whether you're shopping for deals, need help with a little math, or any number of other occasions, it's a valuable skill to know how to quickly figure out a percentage given two numbers.

### How To: Calculate percent composition for chemistry

To calculate percentage composition we will take the example CO2 it stands for Carbon-Di-Oxide. It is the composition of Carbon and Oxygen. We have one carbon and its weight is 12.01 and 2 oxygen. So, we will multiply 2 with 16.00 which is the weight of the oxygen.

### 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 least common multiple in rational expressions

This series walks you through the steps of finding the least common multiple in rational expressions. This excellent video shows you a clean board, 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: 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: 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: 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: 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: 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: 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 Volume of Composite Figures (Also Called Composite Shapes)

Composite figures are composed of several geometric shapes and are three-dimensional shapes. The first composite shape is a combination of a rectangular prism and a pyramid. To find the volume of the entire shape you find the volume of each individual shape and add them together. The second figure consists of a cylinder and a hemisphere. Check out the video below for the full lesson.

### How To: Solve equations with the order of operations

In mathematics, the order of operations define the priority in which complex equations are solved. The top priority is your parenthesis, then exponents, followed by multiplication and division, and finally addition and subtraction (PEMDAS). This video tutorial demonstrates the order of operation with various examples and explains the associated methodology. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autod...

### 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: 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 the equation of a circle given: center & tangent

In this video, the instructor shows how to find the equation of a circle given its center point and a tangent line to it. To do this, take a graph and plot the given point and the tangent on that graph. Now, from the center of the circle, measure the perpendicular distance to the tangent line. This gives us the radius of the circle. Using the center point and the radius, you can find the equation of the circle using the general circle formula (x-h)*(x-h) + (y-k)*(y-k) = r*r, where (h,k) is th...

### How To: Solve for the missing ratios or proportions

In this video the tutor shows how to solve the missing ratios or proportions. He explains it with an example, where a number in one of the ratios is missing and he intends to find this value. He shows the example of cross multiplication, where you multiply the values on the either side of the equation diagonally and finally solves the equation which results in the value of the unknown value. This is an introductory video explaining how to use rations and proportions to find missing values.

### 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: Calculate probability in "at least one" problems

Calculating probablities can be used to help us make decision. PatrickJMT explains how to calculate probability in an "either A or not A" scenario. The probability of A plus the probability of not A is equal to one. Therefore, the probability of A is equal to one minus the probability of not A ; P(A)= 1 - P(not A). The probability of a major earthquake in San Francisco over a period of time is used as an example. The probablity of an earthquake of a magnitude of 7.5 or greater in San Francisc...

### How To: Square expressions involving radicals

Here we look at squaring expressions that involve radicals because people tend to make some common mistakes while solving such expressions. Take 5 times the square root of y quantity squared, the answer here is not 5y. Here's the reason, square means to multiply something with itself so the square of 5 root y would be 5 root y into 5 root y. So 5 x 5 is 25 and under root y into under root y equals just y so the answer will be 25y.

### How To: Calculate the growth rate or percentage change between two numbers

The concept of percentage growth or decline is confusing to a lot of people. If you're one of those people, watch this video. It breaks down how percentage change and growth rates work and how you can calculate them from any pair of numbers.

### How To: Evaluate factorials with a TI-83 calculator

The factorial of a number n can be defined as the product of all positive integers that are greater than 0 but less than or equal to n.

### 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: Find a transformation matrix with respect to a basis

Learn how to find a transformation matrix with respect to a non-standard basis in linear algebra. 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: Use a TI-89 to calculate nCr

This video shows you how to do a mathematical representation on computing the nCr function using a TI-89 calculator. You can write the nCr notation in different forms. It can be simplified from nCr to C(n,r). The symbol can either be read "n choose r" or "n taken r at a time" which are from it's probability applications. On the example to find "26 choose 17", go to the Home screen of the TI-89 calculator and then go 2nd 5 which is Math. Go choose probability and then to nCr to type in (26,17)...

### How To: Solve direct proportions

You can solve any proportion using the fundamental rule of proportions. First you must build the proportion if you are given a word problem. Decide using logic whether it is a direct proportion (more on one side means more on the other). If so, find the parts of the equation that use the same units and make a fraction with these, putting the smaller number on top. The number left over is linked with one of the other two numbers in the fraction--use logic to figure out which. Put it in the sam...

### How To: Find percent by mass & percent composition

In chemistry you come across problems which ask you to find the percent by mass and percent composition of each element in a chemical compound. To do this the first step is to compute the molar mass. Use the periodic table to look up the mass of individual atoms and multiply it by the number of atoms to find the mass of that element. Now add up all the masses to arrive at the molar mass of the compound. Now to find the percent composition of an element divide the total mass of each element by...

### How To: Isolate a variable

If you're struggling a bit with algebra, check out this video to learn how to isolate a variable. Isolating a variable is a matter of separating and simplifying.

### How To: Use applications of rational expressions in algebra

Lawrence Perez, from Saddleback College, and his assistant Charlie, give this beginning-algebra lesson on word problems (or applications) with equations of rational expressions. If you like math, and you like English, than what's the problem?

### How To: Simplify a complex fraction w/ binomial denominators

To simplify a complex fraction, turn it into one fraction on the top divided into a fraction on the bottom. Once this is complete, you will turn the division into the two into a multiple by the reciprocal, factor, and then cancel. To make a division, find the lowest common denominator of both the top and the bottom. Once you get this division equation, look carefully at the equations. If something can be easily canceled, go ahead and cancel it out at this time. If you cannot cancel anything a...

### How To: Know if matrices can be multiplied

In this Education video tutorial you will learn how to know if matrices can be multiplied. If the column of the first and the row of the second match, you can multiply them. For example if, matrix A has 2 rows and 3 columns (A: 2x3) and matrix B has 3 rows and 4 columns (B: 3x4), then you can multiply them. But, if A: 3x2 and B: 3x4, you cannot multiply them. The shape of the resultant matrix will be the shape of the outer numbers. For example, we saw that if A:2x3 and B :3x2, then they can b...

### How To: Derive the basic area of a triangle

In this video tutorial, viewers learn how to solve the area of a triangle. The formula for the area of a triangle is A = ½ x b x h or bh/2. The base of the triangle is always at the bottom; it is the side that the triangle sits on. The height is the length between the base and the highest point of the triangle. Multiply the base and height of a triangle; then divide by two or multiply by half. The measurement unit of the answer should be squared. This video will benefit those viewers who need...

### 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: Evaluate functions by substituting in the variable to the input given

In this video, we learn how to evaluate functions. When evaluating functions, you substitute in the variable to the input given. Once you do this, you will rewrite the equation filing in the appropriate spots with the numbers that you are given. After this, you will evaluate the equation with the proper steps in math. Once you have figured out the problem, you can do this in reverse to make sure you have the correct answer. This is a very easy process and it doesn't take that long. Just make ...

### How To: Understand & calculate percentages with word problems

This video begins with teaching of percentage lesson. He is also teaching conversion of percentage to decimal and vise verse. This teaching is using advanced technology note pad when he goes on writing on pad that will display on screen. He is telling that percent 35% in decimal it is .35 and if decimal 2 it is 20% in percent. And he was teaching how to convert fraction to percent by taking one example 7/8 , to convert this first we have to divide 7 by 8 then we get answer .875 then to conver...

### How To: Find the area of a circle when you know the diameter

In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...

### How To: Find the equation of trig functions by their graphs

Need to know how to determine the equations of trigonmetric functions by inspecting their graphs? Learn how. Learn how to use trigonometric functions to calculate the sides of a right triangle. Need to know how to solve a matrix-form linear equation in algebra? 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 f...

### 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.