Chapter 6 - The Circular Functions and Their Graphs - 6.5 Graphs of the Tangent and Cotangent Functions - 6.5 Exercises - Page 623: 21

see graph.

For $y=-2tan(\frac{1}{4}x)$, we can identify its period as $p=\frac{\pi}{1/4}=4\pi$ and its graph as a result of transformation from $y=tan(x)$ stretching horizontally by a factor of $4$, stretching vertically by a factor of $2$, then reflecting around the x-axis, see graph.