Question

Хелп, производные, 297 и 298

Answer 1

$297)\; \; f(x)=\frac{3-x}{2+x}\\\\f'(x)=\frac{-(2+x)-(3-x)}{(2+x)^2}=\frac{-5}{(2+x)^2}\\\\f'(0)=-\frac{5}{4}=-1,25\; ,\; \; f'(-3)=\frac{-5}{1}=-5\; ,\; \; f'(2t)=-\frac{5}{(2+2t)^2}=-\frac{5}{4(1+t)^2}$

$298)\; \; \; f(x)=x-4\sqrt{x}\\\\f'(x)=1-4\cdot \frac{1}{2}\cdot x^{-\frac{1}{2}}=1-\frac{2}{\sqrt{x}}\\\\f'(4)=1-\frac{2}{2}=1-1=0\; \; ,\; \; f'(0,01)=1-\frac{2}{0,1}=1-20=-19\; \; ,\\\\f'(2-x)=1-\frac{2}{\sqrt{2-x}}$