Calculus 10th Edition

$x^2 + y^2 = 25$ $2x \frac{dx}{dt} + 2y\frac{dy}{dy} = 0$ a) find dy/dt when x = 3, y=4 and dx/dt = 8 $2(3)(8) + 2(4)\frac{dy}{dt} = 0$ $\frac{dy}{dt} = -6$ b) find dx/dt when x = 4, y=3 and dy/dt = -2 $2(4)\frac{dx}{dt} + 2(3)(-2) = 0$ $\frac{dx}{dt} = 1.5$