三角形三个顶点A(1,2)B(4,1)C(3,4),1.求AB边上的中线 2.在AB上取一点P,使过P且平行与BC的直线

M(5/2,3/2)
CM^2=(3-5/2)^2+(4-3/2)^2
CM=√26/2
2)(AP/AB)^2=4/(4+5)
AP/AB=2/3,P(X,Y)
(1-X)/(1-4)=2/3,X=3
(2-Y)/(2-1)=2/3,Y=4/3
P(3.4/3)