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### How to Graph Linear Inequalities

You can use the slope-intercept form to graph inequalities. The *slope-intercept form* is expressed as *y = mx + b*, where the variable *m* stands for the slope of the line, and [more…]

### How to Use a Graphing Calculator

It’s a good idea to purchase a graphing calculator for pre-calculus work. Since the invention of the graphing calculator, math classes have begun to change their scope. A graphing calculator does so many [more…]

### Comparing Radicals and Exponents

Radicals and exponents (also known as *roots* and *powers*) are two common — and oftentimes frustrating — elements of basic algebra. And of course they follow you wherever you go in math, just like a cloud [more…]

### How to Rewrite Radicals as Exponents

When you’re given a problem in radical form, you may have an easier time if you rewrite it by using *rational exponents*— exponents that are fractions. You can rewrite every radical as an exponent by using [more…]

### How to Rationalize a Radical Out of a Denominator

A convention of mathematics is that you don’t leave radicals in the denominator of an expression when you write it in its final form. Thus we do something called [more…]

### How to Vertically Transform Parent Graphs

When you apply a *vertical* *transformation* to a parent graph, you are stretching or shrinking the graph along the *y**-*axis, which changes its height. A number [more…]

### How to Horizontally Transform Parent Graphs

*When you apply a h**orizontal transformation* to a parent graph, you are stretching or shrinking the graph horizontally, along the *x-*axis. A number multiplying a variable inside a function affects the horizontal [more…]

### How to Translate a Function's Graph

When you move a graph horizontally or vertically, this is called a *translation.* In other words, every point on the parent graph is translated left, right, up, or down. Translation always involves either [more…]

### How to Reflect a Function's Graph

*Reflections* take a parent function and provide a mirror image of it over either a horizontal or vertical line. You’ll come across two types of reflections: [more…]

### How to Graph Functions with More than One Rule: Piece-wise Functions

Functions with more than one rule (called *p**iece-wise functions*) are broken into pieces, depending on the input. Although a piece-wise function has more than one function, each function is defined only [more…]

### How to Graph a Rational Function with Numerator Having the Higher Degree

After you calculate all the asymptotes and the *x-* and *y-*intercepts for a rational function, you have all the information you need to start graphing the function. Rational functions where the numerator [more…]

### How to Break Down a Composition of Functions

A *composition* of functions is one function acting upon another. Think of it like putting one function inside of the other — *f*(*g*(*x*)), for instance, means that you plug the entire [more…]

### How to Adjust the Domain and Range of Combined Functions

When you begin combining functions (like adding a polynomial and a square root, for example), the domain of the new combined function is affected. The same can be said for the range of a combined function [more…]

### How to Graph the Inverse of a Function

If you’re asked to graph the inverse of a function, you can do so by remembering one fact: a function and its inverse are reflected over the line *y* = *x.* [more…]

### How to Invert a Function to Find Its Inverse

If you’re given a function and must find its inverse, first remind yourself that domain and range swap places in the functions. Literally, you exchange [more…]

### How to Determine the Length of an Arc

Knowing how to calculate the circumference of a circle and, in turn, the length of an *arc* — a portion of the circumference — is important in pre-calculus because you can use that information to analyze [more…]

### How to Graph a Cosine Function

The parent graph of cosine looks very similar to the sine function parent graph, but it has its own sparkling personality (like fraternal twins). Cosine graphs follow the same basic pattern and have the [more…]

### How to Calculate an Angle Using Reciprocal Trigonometric Functions

Three trigonometric ratios — secant, cosecant, and cotangent — are called *reciprocal functions* because they're the reciprocals of sine, cosine, and tangent. These three functions open up three more ways [more…]

### How to Calculate an Angle Using Inverse Trigonometric Functions

Almost every function has an inverse. An *inverse function*basically undoes a function. The trigonometric functions sine, cosine, and tangent all have inverses, and they're often called [more…]

### How to Draw Uncommon Angles

Many times in your journey through trigonometry — actually, all the time — drawing a figure will help you solve a given problem. So what do you do if you're asked to draw an angle that has a measure greater [more…]

### How to Work with 30-60-90-Degree Triangles

All 30-60-90-degree triangles have sides with the same basic ratio. If you look at the 30–60–90-degree triangle in radians, it translates to the following: [more…]

### How to Graph Polynomials

Although it may seem daunting, graphing polynomials is a pretty straightforward process. Once you have found the zeros for a polynomial, you can follow a few simple steps to graph it. [more…]

### How to Find a Greatest Common Factor in a Polynomial

No matter how many terms a polynomial has, you always want to check for a greatest common factor (GCF) first. If the polynomial has a GCF, factoring the rest of the polynomial is much easier because once [more…]

### How to Use the FOIL Method to Factor a Trinomial

For polynomials with a nonprime leading coefficient and constant term, you can use a procedure called the *FOIL method* of factoring (sometimes called the [more…]

### How to Factor a Perfect Square

FOIL stands for multiply the *first, outside, inside,* and *last* terms together. When you FOIL a binomial times itself, the product is called a *perfect square.* [more…]