## Calculus 10th Edition

$y = 3x^2 - 5x$ $\frac{d}{dt} (y) = \frac{d}{dt} ( 3x^2 - 5x)$ $\frac{dy}{dt} = 6x \frac{dx}{dt} - 5\frac{dx}{dt} = (6x -5)\frac{dx}{dt}$ a) find dy/dt when x = 3 and dx/dt = 2 $\frac{dy}{dt} = 6x \frac{dx}{dt} - 5\frac{dx}{dt} = (6x -5)\frac{dx}{dt}$ $\frac{dy}{dt} = 6(3)(2) - 5(2) = 36 - 10 = 26$ b) find dx/dt when x = 2 and dy/dt = 4 $4 = (6(2)-5) \frac{dx}{dt}$ $\frac{dx}{dt} = 4/7$