Question

In reperul cartezian xOy se considera punctele M(1, 2), A(5,1) și B(0, -1). Determinați lungimea vectorului u= vectorul MA+ vectorul MB.

Answer 1

MA(vector)=(xA-xM)i+(yA-yM)j

MB(vector)=(xB-xM)i+(yB-yM)j

MA(vector)+MB(vector)=(xA+xB-2xM)i+(yA+yB-2yM)j

MQ(vector)=MA(vector)+MB(vector)=(xA+xB-2xM)i+(yA+yB-2yM)j=(xQ-xM)i+(yQ-yM)j

xQ=xA+xB-xM ; yQ=yA+yB-yM

|MQ|=√[(xQ-xM)²+(yQ-yM)²]=√[(5+0-2*1)²+(1-1-2*2)²]=√(1²+(-4)²)=√15