f.4 maths m1 (differentiation)

1. the value of f '(2) of f(x)= (2/x) - 1/√x - x^3
f'(x) = -1*[2x^(-1-1)] - [-1/2(x^(-1/2-1))] - 3x^2
=-2/x^2 + 1/2x^(3/2) - 3x^2
f'(2) = (-100+√2)/8

find the derivative of each of the following functions with respect to x.
2. y=(x+1)(x+2)(x+3)
= x^3+6x^2+11x+6
dy/dx= 3x^2+12x+11

3. y=(2x-1)(3x+4)(x+7)
=6x^2+47x^2+31x-28
dy/dx=18x^2+94x+31