Question

If $1-\frac{1}{3}+\frac{1}{5}-\frac{1}{7}+\frac{1}{9}-\frac{1}{11}+\ldots .=\frac{\pi}{4}$, then value of $\frac{1}{1 \times 3}+\frac{1}{5 \times 7}+\frac{1}{9 \times 11}+\ldots \ldots$ is

• A. $\frac{\pi}{8}$
• B. $\frac{\pi}{6}$
• C. $\frac{\pi}{4}$
• D. $\frac{\pi}{36}$

Answer 1

Answer: (A)

Correct answer is (a) $\frac{\pi}{8}$