Question

Find the angle between Oy axis and vector a{1,squareroot of 2,1} ?

Thanks!

Answer 1

Angle between them are
\[\theta=\cos^{-1}\frac{\sqrt2}{2}=\frac{\pi}{4}\]

Answer 2

Nice!
How do you count that?

Answer 3

Find unit vector along the a<1,sqrt(2),1> which is 0.5<1,sqrt(2),1> take dot product with unit vector along OY