b/a=√2+1
则a/b=1/(√2+1)=√2-1
原式=1/2*(a²+b²)/ab
=1/2*(a²/ab+b²/ab)
=1/2*(a/b+b/a)
=1/2*(√2-1+√2+1)
=√2则a/b=1/(√2+1)=√2-1的答案“根号2-1”怎么来分母有理化什么意思= (√2-1)/(√2-1)(√2+1)=(√2-1)/(2-1)=√2-1