If `sin^(-1) ((4x)/(x^(2) + 4)) + 2 tan^(-1) (-(x)/(2))` is independent of x, find the value of x

Explanation

`E = sin^(-1) ((4x)/(x^(2) + 4)) + 2 tan^(-1) (-(x)/(2))`
`= sin^(-1) ((2 xx (x)/(2))/(((x)/(2))^(2) + 1)) -2 tan^(-1). (x)/(2)`
`= 0` (For E to be independent of x)
`rArr |(x)/(2)| le 1`
or `|x| le 2 " or " -2 le x le 2`