( 2-(2)^(1/2) )^(1/2) / ( 2+(2)^(1/2) )^(1/2)
更新1:
答案係 ( (2)^(1/2) - 1 ) / 2 請列明詳細步驟,因為我唔係好明....
更新2:
SORRY,係 (2)^(1/2) - 1 ....