Question

differentiate. f(x)=\frac{1}{2x - 9} f(x)=square

Explanation:

Step1: Rewrite the function

$F(x)=(2x - 9)^{-1}$

Step2: Apply chain - rule

Let $u = 2x-9$, then $F(u)=u^{-1}$. $F^\prime(u)=-u^{-2}$ and $u^\prime = 2$. So $F^\prime(x)=-2(2x - 9)^{-2}=-\frac{2}{(2x - 9)^2}$

Answer:

$-\frac{2}{(2x - 9)^2}$