Question

Find the derivative of x^2f(x)
A. x[xf'(x)+2f(x)]
B. 2xf'(x)
C. x[xf'(x) +2f'(x)]
D. x^2f'(x)
E. None of these

Answer 1

x^2 f' + 2 x f
= x [ x f' + 2 f ]