Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

The value of $\lim\limits_{x→0}\left(\frac{1-cosx}{2x^2}\right)$ is :

Options:

1

$\frac{1}{2}$

$\frac{1}{4}$

0

Correct Answer:

$\frac{1}{4}$

Explanation:

The correct answer is Option (3) → $\frac{1}{4}$

$\lim\limits_{x→0}\frac{1-\cos x}{2x^2}=\lim\limits_{x→0}\frac{2\sin^2\frac{x}{2}}{2x^2}$

$=\lim\limits_{x→0}\frac{\sin^2(\frac{x}{2})}{(\frac{x}{2})^24}=\frac{1}{4}$