How do I find the dot product of vectors #v =5i-2j# and #w=3i+4j#?
The dot product is a scalar obtained by multiplying the corresponding components of the two vectors and adding (algebraically) the results.
So you have:
You may check your result by plotting your vectors and using the alternative definition of dot product:
i.e.: the product of the modulus of the vectors times de cosine of the angle between them.
After some inverse trigonometry and Pitagora's Theorem I got: