What is \frac{p^2+q^2}{p^2q^2} equal to?

For the following two (02) items: Let p = \csc 20^\circ and q = \csc 70^\circ.

  1. A. 1/2
  2. B. 1
  3. C. 3/2
  4. D. 2

Correct Answer: B. 1

Explanation

The expression simplifies to \frac{1}{q^2} + \frac{1}{p^2}. Substitute the definitions to get \sin^2 70^\circ + \sin^2 20^\circ. Since \sin 70^\circ = \cos 20^\circ, this is \cos^2 20^\circ + \sin^2 20^\circ = 1.

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