A)√7-2
B)2-√7
C)(1/3)(√7-2)
D)(1/3)(2-Thank You
We have, \(\frac {2tan \frac {\alpha}{2}}{1+tan^2 \frac {\alpha}{2}}+\frac {1-tan^2 \frac {\alpha}{2}}{1+tan^2\frac {\alpha}{2}}=\frac {\sqrt 7}{2}\)
You can take, \(tan \frac {\alpha}{2} = t\) if it is convenient and solve for t. That value of t must be chosen for which \(0<\alpha<\frac {\pi}{6}\).