If x2+y2+z2=r2, then tan−1xyzr+tan−1yzxr+tan−1xzyr=
π
π2
0
none of these
We have,
tan−1xyzr+tan−1yzxr+tan−1xzyr
=tan−1 xyzr+yzxr+xzyr−xyzr31−x2+y2+z2r2=tan−1∞=π2