Evaluate:

(i)


(ii)


(iii) Cos 48° – sin 42°


(iv) Cosec 31° – sec 59°


(i)



= 1


(ii)





(iii) cos 48o - sin 42o


= cos (90o - 42o) – sin 42o


= sin 42o - sin 42o


= 0


(iv) cosec 31o - sec 59o


= cosec(90o - 59o) – sec 59o


= sec 59o - sec 59o


= 0


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