如图,在平面直角坐标系中,点B坐标为(x,y),且x,y满足|x+y-6|+(x-y)2=0
1个回答

(1)∵ |x+y-6|+(x-y)²=0

∴ |x+y-6|=0, (x-y)²=0

x+y-6=0, x-y=0

解得:x=3, y=3

∴点B的坐标是(3,3)

(2)如图示:

过B作BE⊥Y轴,垂足为E,过B作BF⊥X轴,垂足为F,

则∠EBF=90°=∠ABF+∠ABE

∵BC⊥AB

∴∠ABC=90°=∠CBE+∠ABE

∴∠CBE=∠ABF(同角的余角相等)

由(1)知BE=BF=3

又∵∠CEB=∠AFB=90°

∴△CEB≌△AFB(ASA)

∴CB=AB(全等三角形的对应边相等)

即:AB=BC