Differentiation

[b521]

If y = x³ + 2x
and
dx/dt = 5,
find
dy/dt when x = 2.

I'm not really sure how to solve this problem at all. It's the first I've seen like this so I don't know what approach I should take.

 

[Deleted member 4993]

If y = x³ + 2x
and
dx/dt = 5,
find
dy/dt when x = 2.

I'm not really sure how to solve this problem at all. It's the first I've seen like this so I don't know what approach I should take.

Use chain rule of differentiation

\(\displaystyle \frac{dy}{dt} \ \ = \ \ \frac{dy}{dx}\cdot \frac{dx}{dt}\)

 

[b521]

Thank you very much!