Answer
$ a.\quad h(k(x))=x$ and $k(h(x))=x$
$ b.\quad$ see image
$ c.\quad$
At $(2,2),$
the tangent to the graph of $h$ has slope $ 3$
the tangent to the graph of $k$ has slope $\displaystyle \frac{1}{3}$
At $(-2,-2),$
the tangent to the graph of $h$ has slope $ 3$
the tangent to the graph of $k$ has slope $\displaystyle \frac{1}{3}$
$ d.\quad$
At $(0,0),$
the tangent to the graph of $h$ is the x-axis
the tangent to the graph of $k$ is the y-axis
Work Step by Step
$ a.\quad$
$h$ and $k$ are inverses $\Leftrightarrow h(k(x))=x$ and $k(h(x))=x$
$h(k(x))=\displaystyle \frac{[g(x)]^{3}}{4}=\frac{[(4x)^{1/3}]^{3}}{4}=\frac{4x}{4}=4$
$k(h(x))=[4h(x)]^{1/3}=[4\displaystyle \cdot\frac{x^{3}}{4}]^{1/3}=[x^{3}]^{1/3}=x$
$h$ and $k$ are inverses of each other.
$ b.\quad$
See attached image.
$ c.\quad$
$h(x)=\displaystyle \frac{1}{4}x^{3},\qquad g(x)=(4x)^{1/3}$
$h'(x)=\displaystyle \frac{3}{4}x^{2},\qquad g'(x)=\frac{1}{3}(4x)^{-2/3}\cdot 4=\frac{4}{3\sqrt[3]{16x^{2}}}$
At $(2,2)$ ... $x=2,$
the tangent to the graph of $h$ has slope $h'(2)=\displaystyle \frac{3\cdot 2^{2}}{4}=3$
the tangent to the graph of $k$ has slope $k'(2)=\displaystyle \frac{4}{3\sqrt[3]{16\cdot 4}}=\frac{1}{3}$
At $(-2,-2)$ ... $x=-1,$
the tangent to the graph of $h$ has slope $h'(-2)=\displaystyle \frac{3\cdot(-2)^{2}}{4}=3$
the tangent to the graph of $k$ has slope $k'(-2)=\displaystyle \frac{4}{3\sqrt[3]{16\cdot 4}}=\frac{1}{3}$
$ d.\quad$
At $(0,0)$ ... $x=0,$
the tangent to the graph of $h$ has slope $f'(0)=0$
the tangent to the graph of $k$ has slope $g'(0)=$ undefined.
So the tangent to f is a horizontal line passing through the origin and the x-axis. The tangent to g is a vertical line passing through the origin and the y-axis.