Do you mean "differentiate both sides of this equation with respect to x"? If so, since the left side is just a constant with respect to x, and , you will get . That equation is never true however.

If you mean "differentiate both sides of this equation with respect to a", then, since the right side is a constant with respect to a, and using the product rule and chain rule, .

If neither of those is what you mean, then I have no idea what youdomean.