Question

The number $k$ is such that $\tan \{\arctan (2)+\arctan (20k)\}=k$. The sum of all possible values of $k$ is

• A. $-\frac{19}{40}$
• B. $-\frac{21}{40}$
• C. 0
• D. $\frac{1}{5}$

Answer 1

Answer: (A)

Correct answer is (a) $-\frac{19}{40}$