Assume that x=x(t) and y=y(t)

Question

Let x^2 + y^2 = 16, and suppose that dy/dt = 3 when x = 1.3 and y > 0

Then dx/dt =

Answer 1

If x = 1.3 then y = 3.7828.

2x dx/dt + 2y dy/dt = 0

2(1.3) dx/dt + 2(3.7828)(3) = 0 and solve for dx/dt

dx/dt = -8.7295