Question

Linear algebra question:
Find the minimum angle between the vectors:
3i+j and -i+j
How do I have to reason?

Answer 1

Do you know how to find the dot product of the two vectors given?

Answer 2

you will have to use the formula
\[\theta=\cos^{-1}(\frac{u \cdot v}{||u|| \cdot ||v||})\]

Answer 3

a·b = ||a|| ||b|| cos(theta)

Answer 4

All right...

Answer 5

If I do the calculations I get \[\cos^{-1} (\frac{ -1 }{ \sqrt{5} })\]

Answer 6

Can you check if it's correct? Thank you for your help.

Answer 7

looks good

Answer 8

ah ok. Thank you very much :)