Question

$\underset{x\to 0}{\lim }\frac{1-\cos x}{x^2}$ is equal to

• A. 2
• B. 3
• C. 1/2
• D. 1/3

Answer 1

Answer: (C)

$\underset{x\to 0}{\lim }\frac{1-\cos x}{x^2}$
$=\underset{x\to 0}{\lim }\frac{\sin x}{2x}$ [using L' Hospital's rule]
$=\frac{1}{2}$