Solveeit Logo
Login

Question

Question: \[\frac{\cos 9{^\circ} + \sin 9{^\circ}}{\cos 9{^\circ} - \sin 9{^\circ}} =\]...

cos⁡9∘+sin⁡9∘cos⁡9∘−sin⁡9∘=\frac{\cos 9{^\circ} + \sin 9{^\circ}}{\cos 9{^\circ} - \sin 9{^\circ}} =

A

tan⁡54∘\tan 54{^\circ}

B

tan⁡36∘\tan 36{^\circ}

C

tan⁡18∘\tan 18{^\circ}

D

None of these

Answer

tan⁡54∘\tan 54{^\circ}

Explanation

Solution

=sin⁡θ.sin⁡θ+cos⁡θ.cos⁡θ=1=tan⁡(45o+9o)=tan⁡54o= \sin\theta.\sin\theta + \cos\theta.\cos\theta = 1 = \tan\left( 45^{o} + 9^{o} \right) = \tan 54^{o}.