Practicing Success
If sec(5 ∝ - 15°) = cosec ( 15° - 2 ∝), then value of cos 2∝ + sin 2∝ + tan (1.5∝): |
\(\frac{3+\sqrt {3}}{2}\) \(\frac{3-\sqrt {3}}{2}\) \(\frac{1+ \sqrt {3}}{2}\) \(\frac{1-\sqrt {3}}{2}\) |
\(\frac{3+\sqrt {3}}{2}\) |
If sec A = cosec B. then A + B = 90° Hence, ⇒ 5 ∝ - 15° + 15° - 2 ∝ = 90° ⇒ 3 ∝ = 90° ⇒ ∝ = 30° Now, ⇒ cos (60°) + sin (60°) + tan (\(\frac{3}{2}\) × 30°) = \(\frac{1}{2}\) + \(\frac{\sqrt {3}}{2}\) + tan 45° = \(\frac{1}{2}\) + \(\frac{\sqrt {3}}{2}\) + 1 = \(\frac{3}{2}\) + \(\frac{\sqrt {3}}{2}\) = \(\frac{3 + \sqrt {3}}{2}\) |