Question

The point of discontinuity in $\lim_{x \rightarrow 0}\frac{1 - \cos mx}{1 - \cos nx} =$ of f(x) = $m/n$ is

• A. 0
• B. π/4
• C. –π/4
• D. None of these

Answer 1

Answer: (A)

0

Answer 2

Here 1 – cos 4 x ≠ 0 ⇒ cos 4 x ≠ 1⇒ 4x ≠ 0, 2π, 4π 

⇒ x ≠ 0, $\frac { \pi } { 2 }$, π.... ;