Calculus I > Precalculus Review

Even and Odd Functions

A function $ f$ is said to be even if it satisfies $ f(-x) = f(x)$. For example, $ f(x) = x^2$ is even. A function $ f$ is said to be odd if it satisfies $ f(-x) = -f(x)$.

Cubing function. A function $ f$ is called a cubing function if

$\displaystyle f(x) = x^3.
$

The cubing function is an odd function, symmetric with respect to the origin.

\includegraphics{lec03c.ps}

Cube root function. A function $ f$ is called a cube root function if

$\displaystyle f(x) = \sqrt[3]{x}.
$

The cube root function is an odd function. The implied domain of $ f$ consists of the entire real numbers, that is, $ D = (-\infty, \infty)$.

\includegraphics{lec03d.ps}

Absolute value function. A function $ f$ is called an absolute value function if

$\displaystyle f(x) = \vert x\vert
= \left\{\begin{array}{cl}
x & \quad\mbox{ if $x \ge 0$; } \\
-x & \quad\mbox{ if $x < 0$. }
\end{array}\right.
$

The absolute value function is an even function, symmetric with respect to the $ y$-axis.

\includegraphics{lec04a.ps}


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