9^ + 9^ 9^ - 9^ = - Vidyadip

MCQ

$\frac{{\cos 9^\circ + \sin 9^\circ }}{{\cos 9^\circ - \sin 9^\circ }} = $

✓
$\tan 54^\circ $
B
$\tan 36^\circ $
C
$\tan 18^\circ $
D
None of these

✓

Answer

Correct option: A.

$\tan 54^\circ $

a
(a) $1+ tan 9^\circ \over {1 - tan 9^\circ}$

$= \tan \,\left( {{{45}^o} + {9^o}} \right) = \tan {54^o}$.

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