#### Answer

Refer to the graph below.

#### Work Step by Step

RECALL:
The functions $y=a \cdot \sin{bx}$ and $y=a \cdot \cos{bx}$ have:
period = $\dfrac{2\pi}{b}$
amplitude = $|a|$
The given function has $a=-1$ and $b=\pi$ thus
period = $\dfrac{2\pi}{\pi}=2$
amplitude = $|-1| = 1$
To graph the function, perform the following steps:
(1) With a period of $2$, one period of the function is over the interval $[0, 2]$.
(2) Divide this interval into four parts to obtain the x-values $0, \frac{1}{2}, 1, \frac{3}{2}, \text{ and } 2$.
(3) Make a table of values using the x-values above. (Refer to the table below.)
(4) Plot the five points of the table of values then connect them using a sinusoidal curve whose ampliude is $1$.
(5) Repeat the cycle of the graph form one more period, which is $[2, 4]$.
(Refer to the graph in the answer part above.)