Question

if a = tan^(-1)x then the value of sin 2a = ?

Answer 1

$A = {tan}^{- 1} x$

tanA = x

now,

sin2A

$= \frac{2tanA}{1 + {tan}^{2} A} \\</p><p>= \frac{2x}{1 + {x}^{2}}$

Hence, sin2A = $\frac{2x}{{x}^{2} + 1}$