如图所示,已知点A(4,0),B(4,4),C(2,6),求AC和OB的交点P的坐标.

问题描述:

如图所示,已知点A(4,0),B(4,4),C(2,6),求AC和OB的交点P的坐标.

OP
=t
OB
=t(4,4)=(4t,4t),
AP
=
OP
-
OA
=(4t,4t)-(4,0)
=(4t-4,4t),
AC
=(2,6)-(4,0)=(-2,6).
AP
AC
共线的充要条件知(4t-4)×6-4t×(-2)=0,解得t=
3
4

OP
=(4t,4t)=(3,3).
∴P点坐标为(3,3).