Consider the two vectors:
L = 4 i + 3 j + k
s = 6 i + 6 j + 8 k
Find the value of the scalar α such that the vector
L - αs
is perpendicular to L.
A [tex]\bullet[/tex] B = |A||B| cos(theta)
A [tex]\bullet[/tex] B = AxBx i + AyBy j + AzBz k
A [tex]\bullet[/tex] A = (Ax^2 + Ay ^2 + Az^2)^.5 (Wouldn't let me do sub and sup in sqrt)
A x B = |A||B| sin(theta)
The Attempt at a Solution
I thought that I could do AxB and set that equal to |A||B| cos(theta) but when I did that everything just canceled out. I am really confused about multiplying a vector by a scalar and how that changes orientation etc.
Any help appreciated!