Barrons AP Calculus - David Bock

Answers Explained

1. (D) Substituting y = 2 yields x = 1. We find y ′ implicitly.
   3 y^2 y ′ − (2 xyy ′ + y^2 ) = 0; (3 y^2 − 2xy)y ′ − y^2 = 0.
   Replace x by 1 and y by 2; solve for y ′.