If sec (5α - 15°) = cosec (15° - 2α) then the value of cosα + sin 2α + tan (1.5α).

\(\sqrt {2}\) + 1 \(\sqrt {2}\) - 1 \(\sqrt {3}\) + 1 \(\sqrt {3}\) - 1

\(\sqrt {3}\) + 1

[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