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Question
Show that: sin 42° sec 48° + cos 42° cosec 48° = 2.
Sum
Solution
L.H.S.
= sin 42° sec 48° + cos 42° cosec 48°
= `sin (90° - 48°) xx (1)/(cos 48°) + cos (90° - 48°) xx (1)/(sin 48°)`
= `cos 48° xx (1)/(cos 48°) + sin 48° xx (1)/(sin 48°)`
= 1 + 1
= 2
= R.H.S.
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