Question

Find the derivative of 30x² + 7x at x = 2.

Answer 1

First differentiate

• d/dx(x^n)=nx^n-1

So

`\\ \rm\Rrightarrow (d)/(dx)(30x^2+7x)`

`\\ \rm\Rrightarrow 60x+7`

Put x=2

• 60(2)+7
• 120+7
• 127

Answer 2

127

Explanation:

Given :

• 30x² + 7x

On differentiating,

• dy/dx = 2 * 30 * x²⁻¹ + 1 * 7 * x¹⁻¹
• dy/dx = 60x + 7

At x = 2

• 60(2) + 7
• 120 + 7
• 127