Calculate the derivative of the function. Then find the value of the derivative as specified. f(x) = f'(-1) Of() - : f'(-1) - 8 O f'(x) = - 8 xz: f-1) = -8 o f'(x) - 8: f-1) - 8 o f(x) = - 8x?: f'(-1) -- 8 O None of these