Actually I have two questions 1. The problem statement, all variables and given/known data Vectors A and B are shown on the figure below. Which one of the following statements is correct? a) A . B = 0 and A × B ≠ 0 b) A . B ≠ 0 and A × B = 0 c) A . B ≠ 0 and A × B ≠ 0 d) A . B = 0 and A × B = 0 Picture: http://i.imgur.com/X0GB9.png 2. Relevant equations A.B = AxBx + AyBy 3. The attempt at a solution Obviously, the answer is zero. but the problem is the difference between A . B and A x B. I have long thought that those two are the same, but this question confused me. I tried google for a bit and found out that [ dot product (u . v) gives a scalar ] and [ cross product (u x v) gives a pseudovector ]. It's my first time hearing about a pseudovector =_= My second question is also about Vectors Multiplication 1. The problem statement, all variables and given/known data A and B are the two vectors shown in the figure. Vector A is along the positive x axis and has a magnitude of 5 cm, and the vector B is in the x-y plane at an angle 30º with the positive x axis and has a magnitude of 4 cm. A × B = a) 20 cm2 in the +x direction b) 10 cm2 in the +y direction c) 10 cm2 in the +z direction d) 20 cm2 in the -y direction 2. Relevant equations A.B = AxBx + AyBy 3. The attempt at a solution When I tried to solve it I got C= 17.5 + 0, so the answer might be a. This cm^2 and the +z confused me, so I just wanted to confirm.