Ex 8.3, 2 - Chapter 8 Class 10 Introduction to Trignometry

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Ex 8.3, 2 Show that : tan 48 tan 23 tan 42 tan 67 = 1 Taking L.H.S tan 48 tan 42 tan 23 tan 67 = tan 48 tan(90 48 ) tan 23 tan(90 23 ) = tan 48 cot 48 tan 23 cot 23 = (tan 48 1/tan 48 ) (tan 23 1/tan 23 ) = 1 1 = 1 = R.H.S L.H.S = R.H.S Hence proved Ex 8.3, 2 Show that : (ii) cos 38 cos 52 sin 38 sin 52 = 0 Taking L.H.S cos 38 cos 52 sin 38 sin 52 = cos (90 52) cos (90 38) sin 38 sin 52 = sin 52 sin 38 sin 38 sin 52 = 0 = R.H.S L.H.S = R.H.S Hence proved