# Thread: The Dot Product - State the angle between the 2 vectors

1. ## The Dot Product - State the angle between the 2 vectors

Staet the angle between the two vectors:

I got

a) 70º

b) 130º

but not sure.
Please help, appreciate all pointers!

2. Originally Posted by advancedfunctions2010
Staet the angle between the two vectors:

I got

a) 70º

b) 130º

but not sure.
Please help, appreciate all pointers!
You do realise that for a line incidend on another line the two angles on the same side of the second line sum to 180 degrees?

CB

3. If you mean that a is a vector making an angle of 100 degrees with the x-axis, up and to the right, and that b is an angle making an angle of 30 degrees with the x-axis, down and to the left, then you simply add those two angles. But I don't understand why you are giving two answers. Those two vectors have one angle between them.

4. Originally Posted by HallsofIvy
If you mean that a is a vector making an angle of 100 degrees with the x-axis, up and to the right, and that b is an angle making an angle of 30 degrees with the x-axis, down and to the left, then you simply add those two angles. But I don't understand why you are giving two answers. Those two vectors have one angle between them.
There are two questions, question a) and question b) as far as I can see, and both the proposed answers are wrong (for the reasons I hinted at).

CB