# Scalar dot product

Calculate u.v if |u| = 5, |v| = 2 and when angle between the vectors u, v is:

a) 60°
b) 45°
c) 120°

Result

a =  5
b =  7.071
c =  -5

#### Solution:

$a=5 \cdot \ 2 \cdot \ \cos 60 ^\circ =\cos π/3=0=5$
$b=5 \cdot \ 2 \cdot \ \cos 45 ^\circ =\cos π/4=0=7.071$
$c=5 \cdot \ 2 \cdot \ \cos 120 ^\circ =\cos 2π/3=0=-5$

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Tips to related online calculators
Two vectors given by its magnitudes and by included angle can be added by our vector sum calculator.
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