Question

Пусть f(x)=√1-2x.Вычислите f'(3/8)

Answer 1

$\displaystyle \\f(x)=\sqrt{1-2x} \\\\f'(x)=\frac{1}{2\sqrt{1-2x} } \times(1-2x)'=\frac{1}{2\sqrt{1-2x} } \times(-2)=-\frac{1}{\sqrt{1-2x} }$

$\displaystyle f'(\frac{3}{8} )=-\frac{1}{\sqrt{1-2\times\frac{3}{8} } } =-\frac{1}{\frac{1}{2} } =-2$