Question

PLEASE HELP!!!
f(x)= sqrt(x^4-16x^2)
a)Find the domain of f.
b) Find f '(x)
c) Find the slope of the line normal to the graph of f at x = 5

Answer 1

Domain in attachment

Answer 2

b) Find f '(x)
\[\sqrt{(x-4)}+\frac{x}{2\sqrt{x-4}}\]

Answer 3

thank you very much by any chance do you know c