已知a=2+根号3,b=2-根号3,球a/a-根号下ab减根号b/根号下a+根号b
问题描述:
已知a=2+根号3,b=2-根号3,球a/a-根号下ab减根号b/根号下a+根号b
答
a/(a-根号下ab)-根号b/(根号下a+根号b)
=(2+根号3)/[2+根号3-根号(2+根号3)(2-根号3)]-(2-根号3)/(2+根号3+2-根号3)
=(2+根号3)/[2+根号3-1]-(2-根号3)/4
=(2+根号3)/(根号3+1)-(2-根号3)/4
=(1+根号3)/2-(2-根号3)/4
=3/4根号3
答
a/(a-根号下ab)-根号b/(根号下a+根号b)=(2+根号3)/[2+根号3-根号(2+根号3)(2-根号3)]-(2-根号3)/(2+根号3+2-根号3)=(2+根号3)/[2+根号3-1]-(2-根号3)/4=(2+根号3)/(根号3+1)-(2-根号3)/4=(1+根号3)/2-(2-根号3)/4=3/...