3.1: Basic Mathematical Operations
Operations and Expressions
An mfile environment has all of the standard arithmetic operations (addition, subtraction, etc.) and functions (sine, cosine, logarithm, etc.). Table 1 lists the most commonly used operations; in this table, \begin{align*}x\end{align*} and \begin{align*}y\end{align*} are scalars. (A scalar is a single value, as opposed to a vector or matrix which consists of many values.)
Operation  mfile 

\begin{align*}x  y\end{align*} 
x  y 
\begin{align*}x + y\end{align*} 
x + y 
\begin{align*}xy\end{align*} 
x*y 
\begin{align*}\tfrac{x}{y}\end{align*} 
x/y 
\begin{align*}x^y\end{align*} 
x^y 
\begin{align*}e^x\end{align*} 
exp(x) 
\begin{align*}\log_{10}(x)\end{align*} 
log10(x) 
\begin{align*}\ln(x)\end{align*} 
log(x) 
\begin{align*}\log_2(x)\end{align*} 
log2(x) 
\begin{align*}\cos(x)\end{align*} 
cos(x) 
\begin{align*}\sin(x)\end{align*} 
sin(x) 
\begin{align*}\sqrt{x}\end{align*} 
sqrt(x) 
Expressions are formed from numbers, variables, and these operations. The operations have different precedences. The
^
operation has the highest precedence;
^
operations are evaluated before any other operations. Multiplication and division have the next highest precedence, and addition and subtraction have the lowest precedence. Precedence is altered by parentheses; expressions within parentheses are evaluated before expressions outside parentheses.
Example 1
Table 2 below shows several mathematical formulas, the corresponding expressions, and the values that are computed for the expressions.
Example Expressions formula MATLAB Expression Computed Value \begin{align*}5^2 + 4^2\end{align*} 5^2+4^2 41\begin{align*}(5 + 4)^2\end{align*} (5+4)^2 81\begin{align*}\tfrac{2+3}{45}\end{align*} (2 + 3)/(4  5)\begin{align*}\log_{10}(100)\end{align*} log10(100) 2\begin{align*}\ln(4(2 + 3))\end{align*} log(4*(2 + 3)) 2.9957
Useful Tricks
These tricks are occasionally useful, especially when you begin programming with mfiles.
 A semicolon added at the end of a line suppresses the output.
 Often it is useful to split input over multiple lines. To split a statement across multiple lines, enter three periods ... at the end of the line to indicate it continues on the next line.
Example 2
 You could split the expression \begin{align*}\tfrac{2+3}{45}\end{align*} over multiple lines as follows:

(2+3)...

/(45)
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Date Created:
Feb 23, 2012Last Modified:
Sep 15, 2014If you would like to associate files with this section, please make a copy first.