Question

найдите f'(-1) если f(x)=4x^2+3x+7/x​

Answer 1

$f(x)=4x^2+3x+\dfrac{7}{x}$

$f'(x)=4\cdot2x+3+7\cdot\left(-\dfrac{1}{x^2}\right)=8x+3-\dfrac{7}{x^2}$

$f'(-1)=8\cdot(-1)+3-\dfrac{7}{(-1)^2}=-8+3-7=-12$