# How to Enter Math in Rhea

This page shows many of the functions and symbols that you are likely to need while working on the practice problems. *hint hint

## Basics of Rhea/Wiki Math

Math in Rhea is written using the Latex commands. To begin, you need use the math tags like: $formulas$.

## Resources

You should know that there is a host of resources already to help you along. One great page on Rhea is How to type Math Equations. Another resource is Wikipedia's page on Functions, Symbols, and Special Characters.

Commands helpful while doing the practice problems
Description What it looks like What you type
Summations $\sum_{n=-\infty}^\infty x[n]e^{-j2\pi f}$ \sum_{n=-\infty}^\infty x[n]e^{-j2\pi f}
Summations with Delta $\sum_{k=0}^\infty x[n]\delta [n-k]$ \sum_{k=0}^\infty x[n]\delta [n-k]
Fractions $y=x^2/2 +\frac{x}{\phi}$ y=x^2/2 +\frac{x}{\phi}
Integrals $\int\limits_{\alpha}^{\beta}e^\tau\ d\tau$ \int\limits_{\alpha}^{\beta}e^\tau\ d\tau
Braces and Script Characters $\mathcal{F }\left \{ rect(t) \right \}, \mathcal{X}(\omega)$ \mathcal{F }\left \{ rect(t) \right \}, \mathcal{X}(\omega)

How to Format a Long Equation
What it looks like What you type
\begin{align} f(x) &= \int\limits_{0}^{2\pi} sin^2(\theta) \ d\theta \\ &= \int\limits_{0}^{2\pi} \big(1-cos^2(\theta) \big)\ d\theta \\ &= \int\limits_{0}^{2\pi} \bigg( 1-\Big(\frac{1}{2} +\frac{1}{2} cos(2\theta)\Big) \bigg)\ d\theta \\ &= \int\limits_{0}^{2\pi} \frac{1}{2}\ d\theta -\frac{1}{2} \int\limits_{0}^{2\pi} cos(2\theta) \ d\theta \\ &= \pi \end{align} \begin{align}

f(x) &= \int\limits_{0}^{2\pi} sin^2(\theta) \ d\theta \\

&= \int\limits_{0}^{2\pi} \big(1-cos^2(\theta) \big)\ d\theta \\

&= \int\limits_{0}^{2\pi} \bigg( 1-\Big(\frac{1}{2} +
\frac{1}{2} cos(2\theta)\Big) \bigg)\ d\theta \\

&= \int\limits_{0}^{2\pi} \frac{1}{2}\ d\theta -
\frac{1}{2} \int\limits_{0}^{2\pi} cos(2\theta) \ d\theta \\

&= \pi \end{align}

## Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett