Question

tan inverse 1-x/1+x = 1/2 tan inverse x

Answer 1

Please see the attachment

Answer 2

tan^-1(1-x)/1+x=1/2tan^-1x

2tan^-1(1-x)/(1+x) = tan^-1x

apply the formula of 2tan-1 x in terms of tan^-1x so that tan^-1 cancel out on both sides then simply solve it

I hope it is clear to u