What is the domain of $f(x)=\frac{x+5}{\sqrt{x^2-9}}$?
$(-\infty,-3)\cup (3,+\infty)$
$(-5,+\infty)$
$(-\infty ,+\infty )$
$(3,+\infty)$
$(-\infty,-3]\cup [3,+\infty)$
Find the slope of the line tangent to when is equal to .
$y(b)=b^7-b^5+4b^2$
-320160
3
3160
3216
320160
when 
is equal to 
.