(i) LHS = \(\frac{cos 11°+sin 11°}{cos 11° -sin 11°}\)
Dividing numerator And denominator by cos 11°,
= tan 56° = RHS
Hence proved.
(ii) LHS = \(\frac{cos 9°+sin 9°}{cos 9° -sin 9°}\)
Dividing numerator And denominator by cos 9°,
= tan 54° = RHS
Hence proved.
(iii) LHS = \(\frac{cos 8°-sin 8°}{cos 8° +sin 8°}\)
Dividing numerator And denominator by cos 8°,
= tan 37° = RHS
Hence proved.