If x increases at the rate of 2 m/sec at the instant when x = 3 m, y = 1 m, at what rate must y be changing in order that the function 2xy - 3x2y shall be neither increasing nor decreasing?
1
32/21 m/sec; increasing
2
32/21 m/sec; decreasing
3
8/21 m/sec; increasing
4
8/21 m/sec; decreasing