Let → a = ⟨ − 4 , 3 , 5 ⟩ and → b = ⟨ 1 , − 2 , 4 ⟩ . Find → a ⋅ → b .

Question

How can I find a and b?

Answer 1

It looks like they are asking for a dot product.

a⋅b=a₁b₁+a₂b₂+a₃b₃

=(-4)(1)+(3)(-2)+(5)(4)

=-4+-6+20 = 10