Find the values of x such that the angle between the vectors (6, 1, −1),

and (1, x, 0) is 45°.

2 answers

x = 5
AAAaannndd the bot gets it wrong yet again!

since u•v = |u||v|cosθ, you need
6+x = √38*√(1+x^2)/√2
36+12x+x^2 = 19+19x^2
18x^2+12x-17 = 0
x = (1±√(19/2))/3