Im given vectors:
b = x hat + y hat
c = x hat + z hat
The Attempt at a Solution
so I have 2 eq's... one says:
r * s = rscos(theta)
the other is a summation saying multiply x component 1 with x component 2, add y component 1 with y component 2, and so on.
Ok so I start with method 2: 1*1 x hat + 1* 0 y hat + 0*1 z hat
so you end with 1 (my books answer).
But when I use "r * s = rscos(theta)" I find the angle between them is 90 degrees so I get 0.
Whv does 1 formula work in this case but the other doesnt