1) The solution of dydx=x2+y2+12xy , satisfying y(1)=0 is given by A) hyperbola B) circle C) ellipse D) parabola Answer: Option AExplanation: dydx=x2+y2+12xy , ⇒ 2xydy=(x2+1)dx+y2dx ⇒ xd(y2)−y2dxx2=(x2+1x2)dx ⇒ ∫d(y2x)=∫(1+1x2)dx ⇒ y2x=x−1x+C ⇒ y2=(x2−1+Cx) where x=1;y=0 ⇒ 0=1-1+C ⇒ C=0 ∴ The solution is x2−y2=1 i.e, hyperbola