Related Rates in calculus

Question

If y = x³ + 2x and  , find  when x = 2. Give only the numerical answer. For example, if  = 3, type only 3.

Answer 1

This is a straightforward application of the chain rule.

If y = axⁿ + bx^m then dy/dt = nax^n-1(dx/dt) + mbx^m-1(dx/dt).

Just plug in the numbers for a, b, n, m, x and dx/dt.