f(x) = x^2 - \sin(x) + \frac{1}{x}.
(a) Find f(0), f(1), and f(\frac{\pi}{2}).
(b) Vectorize f and evaluate f(x) where x = [0 1 \frac{\pi}{2} \pi].
(c) Create x = linspace(-1,1), evaluate f(x), and plot x vs f(x).
(d) Combine the following three commands into a single command to produce
the plot that you will get at the end of the third command.
x = linspace(-1, 1);
y = f(x);
plot(x,y);
(e) Use fplot to graph f(x) over x from -\pi to \pi.
