Hello! I have a problem in my calculus based physics class regarding vectors. The problem says: Vectors A and B have a scalar product -6.00 and their vector product has magnitude 9.00 what is the angle between these two vectors? Here is how I approached it: -6=|A||B|cos (theta) 9=|A||B|sin (theta) tan (theta)= sin (theta)/cos (theta) tan (theta)=9/-6=-56.31 degrees since the sine is positive and cosine is negative the angle lies in the second quadrant. 180 degrees -56.31 degrees= 123.69 degrees which is approximately 124 degrees. Now, why does the angle between the scalar product and the vector product of A and B give us the angle between A and B? Thanks!