If y equals x cube plus 2x and dx over dt equals 5 what is dy over dt when x equals 2?

Answer 1

y=x3+ 2x, dx/dt=5, x=2, dy/dt=?

Differentiate the equation with respect to t.

dy/dt=3x2*dx/dt

Substitute in known values.

dy/dt=3(2)2 * (5)

dy/dt=60