Question

Find the derivative of f(x) = negative 6/ x at x = 12.

Answer 1

if f(x)=1/x=x^(-1) then f'(x)=(-1)*x^(-2)=-1/x^2
f(x)=-6/x
f'(x)=6/x^2
f'(12)=6/12*12=1/24