Practical 7: Symbolic Toolbox

> Exercise: Evaluating Equations

Consider the function $f(x)=\left(x^{3}+2\right) \sec x$

> Define this function $f$ in the Symbolic Toolbox, by first defining $x$ as a symbolic variable.

> Find $f(0.157)$  by evaluating this function at $x = 0.157$ using the subs command as follows:

y = subs(f,x,0.157)

> Find $f(0.123)$ by evaluating this function at $x=0.123$ using the eval command as follows:

x = 0.123

y = eval(f)

As you can see the difference in these two examples is only in the number of commands you need to use to evaluate the function at a certain $x$.