Question

if y=u cube+2u and u=x+1 find dy/dx​

Answer 1

Answer:

u = x+1

y = u³ + 2u

⇒(x+1)³ + 2(x + 1)

⇒x³ + 3x + 3x² + 1 + 2x +2

$\frac{dy}{dx}$ = $\frac{d(x^{3} + 5x + 3x^{2} + 3)}{dy}$= 2x² + 5 + 6x