①若ab=1则(1/1+a²)+(1/1+b²)的值为?

问题描述:

①若ab=1则(1/1+a²)+(1/1+b²)的值为?
②若x+(1/x)=5则x²+x+(1/x²)+1/x的值为?

(1/1+a²)+(1/1+b²)=(ab/ab+a²)+(ab/ab+b²)=b/a+b+(a/a+b)=a+b/a+b=1x²+x+(1/x²)+1/x=x²+1/x²+x+1/x=(x+1/x)²-2+5=28