`tan^(-1)sqrt((1-cosx)/(1+cosx))*0 le x ltpi` को सरलतम रूप में लिखे |

Explanation

`tan^(-1) sqrt((1-cosx)/(1+cosx)) = tan^(-1) ""sqrt((2sin^(2) ""(x)/(2))/(2 cos^(2)""(x)/(2)))=tan^(-1)|tan ""(x)/(2)|`
` = tan^(-1)(tan""(x)/(2)) = (x)/(2) " "[because 0 le x ltpi therefore 0 le(x)/(2)lt(pi)/(2)]`