how do you differentiate 1/4x^3
I assume you have (1/4)x^3...if so......forget the 1/4 part for a second
And the derivative of x^3, by the Power Rule, is just 3x^2....so...multiplying this by the 1/4, we have
(1/4)*3x^2 = (3/4)x^2 and that's it.....