Angle between two vectors, and

Question

Angle between two vectors, <4,4> and <2,0>

amistre64 · Answer

find dot, and magnitudes; what do you get?

amistre64 · Answer

... or 45 degrees; but thats cheating

lukecrayonz · Answer

Uhh 8+0=8 for dot, and magnitude of both for what reason?

amistre64 · Answer

4,4 ; 16+16 = sqrt(32) = 4sqrt(2)
2,0 ;   4+0   = sqrt(4)   =2
----
8+0 = 8

cos(t) = 8
          ---------  =   1/sqrt(2)
           2*4sqrt(2)

lukecrayonz · Answer

theta=acos<v1+v2>?

amistre64 · Answer

it helps if you can remember the formulas ...

amistre64 · Answer

a.b
----- = cos(t)
|a||b|

lukecrayonz · Answer

What was I looking at then.. What formula is that I just said?! Haha

amistre64 · Answer

i dunno what you posted; might be a new invention

lukecrayonz · Answer

So the answer is 45 degrees? Is there any way of using technology to find this? It's an online class, they promote online technology etc.

amistre64 · Answer

ummm, isnt this technological enough?  your on the internet .....

lukecrayonz · Answer

:P As in some sort of program etc

amistre64 · Answer

dunno, im still trying to work out function on my abacus

lukecrayonz · Answer

Oh they provide a program to input into your calculator for this :P

lukecrayonz · Answer

I have a new question for you, you might love it.