Pre Calculus

Question

Find the dot product between the vectors u and v: u = 6i - j and v = 4i + 2j

Answer 1

the dot product here is

u dot v = u1v1 + u2v2

for this set of values that means taking 6(4) + -1(2) = 24 - 2 = 22

Answer 2

If u = a₁i+ b₁j and v = a₂i + b₂j, then the dot product of u and v is a₁ * a₂ + b₁ * b₂

 

So, the dot product would be 6*4 + (-1)*2. Simplified, this becomes 24 + (-2).

 

Therefore, the dot product between these two vectors is 22.