Which one of the following is correct ?

For the next two (02) items that follow : p = \frac{\sin \theta}{1 + \cos \theta + \sin \theta} and q = \frac{1 + \sin \theta}{1 + \sin \theta - \cos \theta}

  1. A. p - q = 0
  2. B. 2pq - 1 = 0
  3. C. pq - 2 = 0
  4. D. pq - 1 = 0

Correct Answer: B. 2pq - 1 = 0

Explanation

Let \theta = 90^\circ. Then \sin 90^\circ = 1 and \cos 90^\circ = 0. Substituting these values gives p = \frac{1}{1+0+1} = \frac{1}{2} and q = \frac{1+1}{1+1-0} = 1. The product pq = \frac{1}{2} \times 1 = \frac{1}{2}. Thus, 2pq = 1, which means 2pq - 1 = 0.

Related questions on Trigonometry

Practice more CDS Elementary Mathematics questions