✿━━━━@♥ℳg━━━━✿
<h2>______________________________
✿━━━━@♥ℳg━━━━✿
f (x) = log ( 1+x / 1-x ) ---- 1
f ( 2x / 1+x2 ) = ???
to find this ----- in equation 1 replace "x" by ( 2x / 1+x2 )
then
f ( 2x / 1+x2 ) = log ( 1 + x2 + 2x / 1 + x2 - 2x )
f ( 2x / 1+x2 ) = log ( 1+x / 1-x ) 2
f ( 2x / 1+x2 ) = 2 log ( 1+x / 1-x )
f ( 2x / 1+x2 ) = 2 f(x)
Cheers....