Question

Tính độ dài của các vectơ sau

1) a= ( 3,8) ,b=( -3,2), c=( 4,3), d= ( 1,-3)

2) AB=( 1,3) , CD= ( 2, -1) , MN=( -4,1) , PQ=( 2,0)

Answer 1

\(\left|\overrightarrow{a}\right|=\sqrt{3^2+8^2}=\sqrt{73}\) ; \(\left|\overrightarrow{b}\right|=\sqrt{\left(-3\right)^2+2^2}=\sqrt{13}\)

\(\left|\overrightarrow{c}\right|=\sqrt{4^2+3^2}=5\) ; \(\left|\overrightarrow{d}\right|=\sqrt{1^2+\left(-3\right)^2}=\sqrt{10}\)

\(\left|\overrightarrow{AB}\right|=\sqrt{1^2+3^2}=\sqrt{10}\) ; \(\left|\overrightarrow{CD}\right|=\sqrt{2^2+\left(-1\right)^2}=\sqrt{5}\)

\(\left|\overrightarrow{MN}\right|=\sqrt{\left(-4^2\right)+1^2}=\sqrt{17}\) ; \(\left|\overrightarrow{PQ}\right|=\sqrt{2^2+0^2}=2\)