Evaluate the following :

Question :

(i)  \(sin 18\over cos 72\)

(ii)  \(tan 26\over cot 64\)

(iii)  cos 48 – sin 42

(iv)  cosec 31 – sec 59

Solution :

(i)  \(sin 18\over cos 72\) = \(sin 18\over cos (90 – 18)\) = \(sin 18\over sin 18\) = 1

(ii)  \(tan 26\over cot 64\) = \(tan 26\over cot (90 – 26)\) = \(tan 26\over tan 26\) = 1

(iii)  cos 48 – sin 42 = cos(90 – 42) – sin 42 = sin 42 – sin 42 = 0

(iv)  cosec 31 – sec 59 = cosec 31 – sec(90 – 31) = cosec 31 – cosec 31 = 0

Leave a Comment

Your email address will not be published.