令x=2,y=1,则:x三角形y=4/3
所以有:1/2+1/3+1/(m+1)=4/3
解得:m=1
根据上式计算有:x三角形y=1/xy+1/(x+1)+1/(y+1)
所以有:2011三角形2012=1/(2011*2012)+1/2012+1/2013
=1/2011-1/2012+1/2012+1/2013
=1/2011+1/2013
=2024/2011*2013
=2024/4048143
f(x,y)=1/(xy)+1/(x+1)+1/(y+m)
f(2,1)=1/2+1/3+1/(m+1)=3/4>>>>1/(m+1)=-1/12>>>m=-13
f(2011,2012)=(1/2011-1/2012)+1/2012+1/1999=1/2011+1/1999
(1)根据已知将x=2,y=1代入原式,列出方程 易解得m=1
(2)1/2011+1/2013
(1)m=1