a a/b=?
若(1/a) (1/b)=1/(a b),则b/a a/b=?若(1/a)+(1/b)=1/(a+b),则b/a+a/b=?
(1/a)+(1/b)=1/(a+b) (a+b)/ab=1/(a+b) (a+b)^2=ab a^2+b^2=-ab b/a+a/b=(b^2+a^2)/ab=-ab/ab=-1
解: 1/(a+b)=(1/a)+(1/b)=(a+b)/ab 所以 (a+b)^2=ab a^2+b^2=-ab 上式两边同除ab得:b/a+a/b=-1
-1
-1
(1/a)+(1/b)=1/(a+b) 即 (a+b)^2=ab 所以 b/a +a/b =(a^2+b^2)/ab =[(a+b)^2-2ab]/ab =(ab-2ab)/ab =-1
答:a>0,b>0,a+b>2√ab, ab≤[(a+b)/2]^2=1/4 1/a+1/b=(a+b)/ab=1/ab≥1/(1/4)=4 1/a+1/b的最小值...详情>>
答:执行顺序是从右向左的,先执行a*a;=36-----a=a-36=-30------a=a+(-30)=-60 谢谢!`~~`~~~~~~~~~~~~~详情>>