Question

Se considera punctele A,B si C astfel incat AB = 2i + j si BC = i - j .Calculati lungimea vectorului AC

Answer 1

$\overrightarrow{AC}= \sqrt{(x_2-x_1)^2+(y_2-y_1)^2} \\\\ \overrightarrow{AC}=\sqrt{(1-2)^2+(-1-1)^2} \\\\ \overrightarrow{AC}=\sqrt{(-1)^2+(-2)^2} \\\\ \overrightarrow{AC}=\sqrt{1+4} \\\\ \boxed{\boxed{\overrightarrow{AC}=\sqrt{5}}}$