I'm trying to help a friend with the following homework question:
Vectors A and B lie in an xy plane. A has a magnitude of 8.00 units and an angle of 130 degrees; B has components Bx = -7.72 units and By = -9.2 units. Find the angle between the negative direction of y-axis and the direction of the product AxB.
Now I have already calculated B have an angle of 230.11 degrees. I can calculate the angle between the two vectors using the dot product method, but the question asked for the angle between the negative y-axis and the cross-product of the two vectors, the cross-product being a vector that is both perpendicular to both A and B, which is causing a problem for me. Can somebody give me some help in resolving this particular issue? It would be much appreciated.