The standard method to find the derivative of functions of type where and are functions of is by taking logarithm on both sides and proceeding.
On the right side you have this very occurrence. Here, while .
Let's take log both sides and proceed...
Differentiating w.r.t. throughout...
In your original equation if we put x=2,
which is not so we can put in the eqn 2 abv.
Which if we do, the right side of eqn 2 takes the value 1/2.
So, we have, .
So, you can find , now