Question:
Mark $(\sqrt{)}$ against the correct answer in the following:
The solution of the $D E \cos x(1+\cos y) d x-\sin y(1+\sin x) d y=0$ is
A. $1+\sin x \cos y=\mathrm{C}$
B. $(1+\sin x)(1+\cos y)=\mathrm{C}$
C. $\sin x \cos y+\cos x=\mathrm{C}$
D. none of these
Solution:
