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Railways PYQCBT 1 2016

RRB NTPC · Question 27

The value of (sec^2θ + 2tanθcotθ – tan^2θ) is A. 0 B. 1 C. 2 D. 3

  1. A

  2. C

  3. B

  4. D

Show answer & explanation

Answer: (D) D

Explanation

Use sec²θ − tan²θ = 1 and tanθ × cotθ = 1. Then sec²θ + 2tanθcotθ − tan²θ = (sec²θ − tan²θ) + 2(tanθcotθ) = 1 + 2 × 1 = 3.