Q.What is the value of \(\cfrac{9}{\csc^2\theta} + 4\cos^2\theta + \cfrac{5}{1 + \tan^2\theta}\)? (a) 1 (b) 0 (c) 3 (d) 9
Answer: D
\(\cfrac{9}{\csc^2\theta} + 4\cos^2\theta + \cfrac{5}{1 + \tan^2\theta}\) \(= 9\sin^2\theta + 4\cos^2\theta + \cfrac{5}{\sec^2\theta}\) \(= 9\sin^2\theta + 4\cos^2\theta + 5\cos^2\theta\) \(= 9\sin^2\theta + 9\cos^2\theta\) \(= 9(\sin^2\theta + \cos^2\theta) = 9\)
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