AMO 2021 - Secondary 3 (Grade 9) Question 9

Question 9

Two force vectors $\vec u=\overrightarrow{AF_1}$ and $\vec v=\overrightarrow{AF_2}$ act on an object at $A$. Find the resultant vector $\vec u+\vec v$ from the unit grid.

Question illustration

$\langle3,7\rangle$
$\langle8,-1\rangle$
$\langle\sqrt5,-2\rangle$
$\langle6,-4\rangle$
$\langle1,8\rangle$