(11) Let the line $y=a x-4$ be symmetric to the line $y=8 x-b$ with respect to the line $y=x$, then $a=$ $\qquad$ ,$b=$ $\qquad$
$11 \frac{1}{8},-32$ Hint: The equation of the line symmetric to $y=a x-4$ about $y=x$ is
$$
y=\frac{1}{a} x+\frac{4}{a} \Rightarrow \frac{1}{a}=8, \frac{4}{a}=-b \Rightarrow a=\frac{1}{8}, b=-32 .
$$