How to differentiate y=(x^2+4x)^5

To differentiate y=(x2+4x)5 you need to use the chain rule. The chain rule uses the fact that dy/dx = dy/dt * dt/dx. 

Here we create a new variable t, where t = x2+4x. Substituting this in the original equation gives y=t5

Differentiating t=x2+4x with respect to x; dt/dx = 2x+4

Differentiating y=t5 with respect to t; dy/dt = 5t4

We can combine these two equations to find dy/dx, as the chain rule states dy/dx = dy/dt * dt/dx.

This gives dy/dx = 5t4*(2x+4)

Substituting in our value of t, gives the final answer dy/dx = 5(x2+4x)4(2x+4)

AM

Related Maths A Level answers

All answers ▸

Differentiate the function y=4sqrt(x)


Find a local minimum of the function f(x) = x^3 - 2x.


Show that x^2 - 8x +17 <0 for all real values of x


Is AB perpendicular to BC where A =(2,0,-1), B=(4,3,-6) and C = (9,3,-4)