Answer:
B. 0.
Explanation:
(x + 2y)dy/dx = 2x - y
dy/dx = (2x -y)/(x + 2y)
Using implicit differentiation and the Quotient Rule:
d^2y/dx^2 = (x + 2y)(2 - y*dy/dx) - ((2x - y)(1 + 2y*dy/dx)) / (x + 2y)^2
At the point (3, 0), dy/dx = (6-0)/(3 + 2(0)) = 2.
So substituting in d^2y/dx^2, we have:
(3 + 0)(2 - 0) - (6-0)(1 + 2(0))/ (3+0)^2
= (6 - 6) / 9
= 0.