How do you differentiate y=(x+1)^2(2x-1)?

2 Answers
Aug 13, 2017

dy/dx =4x(2x+1)

Explanation:

y=(x+1)^2(2x+1)

Use the product rule and chain rule to differentiate y

Product rule:

d/dx(pq) = qp' + pq'

Chain rule:

d/dx([f(x)]^n) = n[f(x)]^(n-1)f'(x)

dy/dx = 2(x+1)(2x-1) + 2(x+1)= 2(x+1)(2x-1+1) = 4x(2x+1)

Aug 13, 2017

6x(x + 1)

Explanation:

Actually, there are mainly 2 methods of solving your question,

  1. Either simplifying the equation and differentiating it

  2. Or differentiating first and then simplifying it.

Obviously, the first one is the easiest for beginners,

rArr y = (x + 1)^2(2x - 1)

Simplifying this, I get,
rArr y = 2x^3 + 3x^2 - 1

Now,
rArr dy/dx = 6x^2 + 6x

therefore, dy/dx = 6x(x + 1)

ENJOY MATHS !!!!!!!!!