(i) LHS

Dividing numerator And denominator by cos 11°,

We know that

= tan 56° = RHS

Hence proved.

(ii) LHS

Dividing numerator And denominator by cos 9°,

We know that

= tan 54° = RHS

Hence proved.

(iii) LHS

Dividing numerator And denominator by cos 8°,

We know that

= tan 37° = RHS

Hence proved.