What is the range of the function?

Consider the following for the two (02) items that follow : Let the function y=(1-\cos x)^{-1}, where x \neq 2n\pi and n is an integer.

  1. A. [0,\infty)
  2. B. [0.5,\infty)
  3. C. [1,\infty)
  4. D. (-\infty,0.5]

Correct Answer: B. [0.5,\infty)

Explanation

Since -1 \leq \cos x \lt 1, we have 0 \lt 1-\cos x \leq 2. Inverting this gives \frac{1}{1-\cos x} \geq \frac{1}{2}. Thus, y \geq 0.5, making the range [0.5, \infty).

Related questions on Calculus

Practice more NDA Mathematics questions