解1由题知反比例函数y2=k2/x(x>0)的图像过A(2,-4)知k2/2=-4解得k2=-8故y2=-8/x又由该反比例函数图像过点B(m,-1)则-1=-8/m解得m=8故B(8,-1)又由y1=k1x+b图像过点A(2,-4),B(8,-1)知2k1+b=-48k1+b=-1解得k=1/2,b=-5故y=x/2-52由图2知当2<x<8时,y2>y1(3)P(6,3)或P(10,-5)或P(-6,-3).