# Find Angle Between Vectors

• MHB
brinlin
Find the angle between the vectors $$\displaystyle v=-5\sqrt{3}i+5j$$ and $$\displaystyle w=5i$$

## Answers and Replies

skeeter
I'd use the dot product formula ...

$\cos{\theta} = \dfrac{\vec{v} \cdot \vec{w}}{|v| \, |w|}$

brinlin
when we use the dot product formula. What would we plug in for v and w.

skeeter
to calculate the dot product of two vectors given in component form …

$(a \vec{i} + b \vec{j}) \cdot (c \vec{i} + d \vec{j}) = ac + bd$

… note the dot product is a scalar quantity

HOI
when we use the dot product formula. What would we plug in for v and w.
? YOU said, in your first post that
$v= -5\sqrt{3}i+ 5j$
$w= 5i$.