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Algebra
How to Add and Subtract Fractions in Algebra (Video)
In algebra, adding and subtracting fractions is easy when you find the common denominator. This video shows you how to convert fractions for the common denominator. After you determine the common denominator, you can add and subtract fractions, including story problems, with ease. [more…]
Calculus
How to Find the Volume of a Solid with a Circular Cross-Section (Video)
Calculus allows you to calculate the volume of conical objects by dividing the object into an infinite number of circular cross-sections - geometrical shapes resembling pancakes or washers - and adding up the volume of all those cross-sections through integration. This video tutorial shows you how. [more…]
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Geometry
Mastering the Formal Geometry Proof
Suppose you need to solve a crime mystery. You survey the crime scene, gather the facts, and write them down in your memo pad. To solve the crime, you take the known facts and, step by step, show who committed [more…]
Geometry
Sizing Up the Area of a Polygon
Not only can polygons be classified by the number of sides they have and by their angles, but they can also be grouped according to some of their qualities. Polygons can have three personality characteristics [more…]
Geometry
Simple and Easy Geometry Tips and Tools
The first rule of life? Life (as well as geometry) can be difficult. But why make it more difficult than it has to be? Do you need help with geometry? Here are 11 tried-and-true tips to make your forays [more…]
Geometry
Measuring and Making Angles
On a map, you trace your route and come to a fork in the road. Two diverging roads split from a common point and form an angle. The point at which the roads diverge is the [more…]
Geometry
Classifying Three Types of Triangles
Triangles are classified according to the length of their sides or the measure of their angles. These classifications come in threes, just like the sides and angles themselves. That is, a triangle has [more…]
Algebra Workbook For Dummies Cheat Sheet
Formulas, patterns, and procedures used for simplifying expressions and solving equations are basic to algebra. Use the equations, shortcuts, and formulas you find for quick reference. This Cheat Sheet [more…]
Simple Steps for Solving Word Problems
Word problems aren’t just on school tests. You solve word problems every day in your work or even while you’re just out and about. Don’t worry — these steps make solving word problems easier than you think [more…]
Calculating a Standard 15-Percent Tip
Calculating a 15-percent tip in your head may seem tricky, but here’s a, well, tip for those situations when you need to calculate that standard tip amount. And it works 100 percent of the time. In order [more…]
Counting Change for Customers the Old-Fashioned Way
Although many cashiers simply dump all your change in your hand at once, counting change the old-fashioned way ensures that customers get the proper amount. Here’s an easy way to make a customer’s change [more…]
Matching American and Metric Units of Measurement
If you’ve ever had to match American and metric measurement units, you know direct comparisons of these unit systems can be tricky. If you need to know the metric equivalent of an inch, for example, or [more…]
Technical Math For Dummies Cheat Sheet
Grasping some technical math basics can simplify everyday situations faced by many professionals and even non-professionals, including having to solve word problems, calculate tips, make change, or match [more…]
Using Calculators on the SAT
When taking the SAT, you're allowed to use a calculator. Calculators can save a lot of time on the SAT if you save them for when you can't quickly and easily do a calculation in your head. The more complicated [more…]
Topics Covered in the Math Sections of the SAT
You have a much better chance of getting a good SAT math score if you know what to expect. Focusing your study time on what will be included in the math sections of the SAT [more…]
How to Interpret Function Graphs
You’re going to see dozens and dozens of functions in your study of calculus, and the graphs of those functions can visually express such things as inflation, population growth, and radioactive decay. [more…]
How to Horizontally Transform a Function
You can transform any function into a related function by shifting it horizontally or vertically, flipping it over (reflecting it) horizontally or vertically, or stretching or shrinking it horizontally [more…]
How to Vertically Transform a Function
To transform a function vertically, you add a number to or subtract a number from the entire function, or multiply it by a number. To do something to an entire function, say [more…]
How to Solve Limits by Conjugate Multiplication
To solve certain limit problems, you’ll need the conjugate multiplication technique. When substitution doesn’t work in the original function — usually because of a hole in the function — you can use conjugate [more…]
How to Solve Limits at Infinity by Using Horizontal Asymptotes
Horizontal asymptotes and limits at infinity always go hand in hand. You can’t have one without the other. If you’ve got a rational function like [more…]
The Basic Differentiation Rules
Some differentiation rules are a snap to remember and use. These include the constant rule, power rule, constant multiple rule, sum rule, and difference rule. [more…]
How to Work with Lines in Calculus
A line is the simplest function that you can graph on the coordinate plane. (Lines are important in calculus because when you zoom in far enough on a curve, it looks and behaves like a line.) This figure [more…]
How to Recognize Inverse Functions
You can tell that two functions are inverse functions when each one undoes what the other does. When you graph inverse functions, each is a mirror image of the other. Here are some examples of inverse [more…]
How to Use SohCahToa to Find the Trig Functions of a Right Triangle
The study of trigonometry begins with the right triangle. The three main trig functions (sine, cosine, and tangent) and their reciprocals (cosecant, secant, and cotangent) all tell you something about [more…]
How to Graph Sine, Cosine, and Tangent
So, you need to graph a sine, cosine, or tangent function. Sine, cosine, and tangent — and their reciprocals, cosecant, secant, and cotangent — are periodic [more…]
How to Use Limits to Determine Continuity
Here you’ll learn about continuity for a bit, then go on to the connection between continuity and limits, and finally move on to the formal definition of continuity. [more…]
Solving Easy Limits
There are two types of easy limit problems: the ones you should just memorize and the ones where you can plug in the x-number and get the answer in one step. [more…]
How to Solve Limits with a Calculator
You can solve most limit problems by using your calculator. There are two basic methods. For example, say you want to evaluate the following limit: [more…]
How to Solve Limits by Factoring
You can use the algebraic technique of factoring to solve “real” limit problems. All algebraic methods involve the same basic idea. When substitution doesn’t work in the original function — usually because [more…]
How to Solve Limits with Basic Algebra
When substitution doesn’t work in the original limit function — usually because of a hole in the function — you can often use some algebra to manipulate the function until substitution does work [more…]
How to Solve Limits at Infinity with a Calculator
Solving for limits at infinity is easy to do when you use a calculator. For example, enter the below function in your calculator's graphing mode: [more…]
How to Solve Limits at Infinity by Using Algebra
Yes, you can solve a limit at infinity using a calculator, but all things being equal, it’s better to solve the problem algebraically, because then you have a mathematically airtight answer. For example [more…]
