Answer
a) dy/dt = -6
b) dx/dt = 1.5
Work Step by Step
$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 $
