xy^2 = 20 => y^2 = 20/x
[y^2]' = [20/x]'
2y [dy/dt] = [-20/x^2] [dx/dt]
dy/dt = [-10/yx^2] [dx/dt]
[dx/dt] = - 3 u/s ....(the negative sign was included to account for decreasing)
y = 2 => x(2)^2 = 20 => x = 20/4 = 5
dy/dt = [-10/(2*5^2)] [- 3]
dy/dt = [-1/5][- 3] = 3/5
Answer: dy/dt = 3/5 units/s
