Practicing Success
Let $y(x)$ be a solution of $x d y+y d x+y^2(x d y-y d x)=0$ satisfying $y(1)=1$. Statement-1: The range of $y(x)$ has exactly two points. Statement-2: The constant of integration is zero. |
Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. Statement-1 is True, Statement-2 is False. Statement-1 is False, Statement-2 is True. |
Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. |
We have, $x d y+y d x+y^2(x d y-y d x)=0$ $\Rightarrow d(x y)+x^2 y^2\left\{\frac{x d y-y d x}{x^2}\right\}=0$ $\Rightarrow \frac{1}{(x y)^2} d(x y)+d\left(\frac{y}{x}\right)=0$ On integrating, we get $-\frac{1}{x y}+\frac{y}{x}=C$ ....(i) It is given that $y=1$ when $x=1$ ∴ $-1+1=C \Rightarrow C=0$ Putting $C=0$ in (i), we get $-\frac{1}{x y}+\frac{y}{x}=0 \Rightarrow y^2-1=0 \Rightarrow y= \pm 1$ Clearly, statement-1 and statement-2 are true. Also, statement- 2 is not a correct explanation for statement- 1 . |