The value of tan−1[√1+x2+√1−x2√1+x2−√1−x2], |x|<12,x≠0, is equal to.
Prove that tan−1(√1+x2+√1−x2√1+x2−√1−x2)=π4+12cos−1 x2.
If sin−1(x−x22+x34−⋯)+cos−1(x2−x42+x64−⋯)=π2 for 0 < 1x < √2, then x equals