If tanα + sinβ = m cotα + cosecβ = n, α ≠ β, then find the value of cosec2β (\(\frac{m}{n}\))2 + 4. |
sec2α + cot2β cos2β + sec2α tan2α tan2β |
sec2α + cot2β |
Put α = 45°, β = 30° [∵ Two equations and 4 variables are given, put 2 of them any thing] ⇒ tanα + sinβ = m m = 1 + \(\frac{1}{2}\) = \(\frac{3}{2}\) ⇒ cotα + cosecβ = n n = 1 + 2 = 3 Put in find out ⇒ cosec2β (\(\frac{m}{n}\))2 + 4 ⇒ (2)2 × \(\frac{1}{4}\) + 4 = 5 Now check options and satisfy. From option A: ⇒ sec2α + cot2β = (\(\sqrt {2}\))2 + (\(\sqrt {3}\))2 = 5 satisfied ⇒ sec2α + cot2β is the correct answer. |