Question

If A.B=2 and IAI=2, IBI=undroot2 then angle b/w vectors is 45 degree...how?? :/someone explain me please...

Answer 1

To find the angle we use A.B=ABCOStheta right??

Answer 2

cos = a.b/|a||b| yes

Answer 3

to determine the angle itself requires you to take the arccos of the setup

Answer 4

But angle 45 doesn't come when i solve it :/

Answer 5

of course it does ...

Answer 6

\[2\sqrt2~cos=2\]
\[\sqrt2~cos=1\]
\[cos=\frac 1{\sqrt2}\]
\[\theta=cos^{-1}\left(\frac 1{\sqrt2}\right)=\frac{pi}{4}\]