If sec (5α - 15°) = cosec (15° - 2α) then the value of cosα + sin 2α + tan (1.5α).
Answer & explanation
Correct answer: option 3
[Concept: sec A = cosec B, when A + B = 90°]
Therefore,
(5α - 15° + 15° - 2α) = 90°
3α = 90°
α = 30°
Put this value in find →
⇒ cosα + sin 2α + tan (1.5α)
⇒ cos30° + sin60° + tan45°
= \(\frac{\sqrt {3}}{2}\) + \(\frac{\sqrt {3}}{2}\) + 1
= \(\sqrt {3}\) + 1