1. The problem statement, all variables and given/known data Vectors and have scalar product -7.00 and their vector product has magnitude 3.00. What is the angle between these two vectors? 2. Relevant equations |A| |B| cosθ = -7 |A| |B| sinθ = 3 3. The attempt at a solution tanθ = (-3/7) tan-1(-3/7)=θ When I enter tan-1(-3/7) into my calculator, I get -23.199, but when I enter 23.199 into MasteringPhysics, it tells me that I am incorrect. What am I doing wrong? Thanks!