Solution: 1 Mark each
(i)sin 75∘+cosec 75∘
=sin(90∘−15∘)+cosec(90∘−15∘)
=(cos 15∘+sec 15∘)
(ii)tan 65∘+cot 49∘
=tan(90∘−25∘)+cot(90∘−41∘)
=(cot 25∘+tan 41∘)
(iii)sec 67∘+cosec 58∘
=sec(90∘−23∘)+cosec(90∘−32∘)
=(cosec 23∘+sec 32∘)
(iv)cos 83∘−sec 76∘
=cos(90∘−7∘)−sec(90∘−14∘)
=(sin 7∘−cosec 14∘)