Question:
Mark $(\sqrt{)}$ against the correct answer in the following:
The general solution of the $\operatorname{DE}(x-y) d y+(x+y) d x$ is
A. $\tan ^{-1} \frac{\mathrm{y}}{\mathrm{x}}=\mathrm{C} \sqrt{\mathrm{x}^{2}+\mathrm{y}^{2}}$
B. $\tan ^{-1(y-x)}=C \sqrt{x^{2}+y^{2}}$
C. $\tan ^{-1}\left(\frac{y}{x}\right)=x^{2}+y^{2}+C$
D. None of these
Solution:
