Physics - Test Your Knowledge: Vectors (16 of 30) Find Direction Cosine (Dot Product)

In this video I will find the direction cosines of a vector perpendicular to vector A and B using the dot product. Given C is perpendicular to A and C is perpendicular to B and A=2i+3j-k and B=i+2j+k.

To donate:

Next video in this series can be seen at:

[petereziagor]

nice trick here 😺. I like to see this
I think only professors know what a solution is going to be like so they know what is best to do.

[dpmike]

Why didn’t you just eliminate Cz because you have additive inverse …it would have been easier

[Muslimcoder]

Sir is it always mentioned in tge question that find the direction cosine of " Dot product or vector". If not then how can wr identify that the question is demanding the cosine of dot product ot vector?

[NdumelisobrianMudau]

Why is it that you multiplied bottom equation by -2?