- Home
- Standard 11
- Mathematics
3.Trigonometrical Ratios, Functions and Identities
easy
$\tan \frac{A}{2}$ बराबर है
A
$ \pm \sqrt {\frac{{1 - \sin A}}{{1 + \sin A}}} $
B
$ \pm \sqrt {\frac{{1 + \sin A}}{{1 - \sin A}}} $
C
$ \pm \sqrt {\frac{{1 - \cos A}}{{1 + \cos A}}} $
D
$ \pm \sqrt {\frac{{1 + \cos A}}{{1 - \cos A}}} $
Solution
(c) $\tan \left( {\frac{A}{2}} \right) $
$= \frac{{\sin (A/2)}}{{\cos (A/2)}} $
$= \pm \sqrt {\frac{{(1 – \cos A)/2}}{{(1 + \cos A)/2}}} $
$= \pm \sqrt {\frac{{1 – \cos A}}{{1 + \cos A}}} $.
Standard 11
Mathematics