Question

need help on attachment

Answer 1

\[f(x)=x\sqrt{1-x^2}+3\]\[f'(x)=(x)'\sqrt{1-x^2}+x(\sqrt{1-x^2})'=\]\[=\sqrt{1-x^2}+x\frac{-2x}{2\sqrt{1-x^2}}=\sqrt{1-x^2}-\frac{x^2}{\sqrt{1-x^2}}=\]\[=\frac{1-2x^2}{\sqrt{1-x^2}}\]