Question

If y = 2x3 - 4x and dx/dt equals 4 , find dy, dt when x = 1. Give only the numerical answer. For example, if dy, dt = 3, type only 3.

Answer 1

Answer: 8

Step-by-step explanation:

Given that

dx/dt= 4

y= 2x^3-4x

Differentiate the above equation with respect to x as follow:

dy/dx= 6x^2-4

Using dx/dt=4 in the above equation, we get:

dy/(4dt)= 6x^2-4

dy/dt= 4*(6*x^2-4)

We need to calculate dy/dt at x=1.

So,

dy/dt= 4*2

dy/dt= 8