2. (1 pt) If A = [a11 a12; a21 a22] and B = [b11 b12; b21 b22] are arbitrary vectors in M2(R), then the mapping <A, B> = a11b11 + a12b12 + a21b21 + a22b22 defines an inner product in M2(R). Use this inner product to determine <A, B>, ||A||, ||B||, and the angle aA,B between A and B for A = [5 -2; 4 -2] and B = [-5 -2; 1 1].
<A, B> = __________,
||A|| = __________,
||B|| = __________,
aA,B = __________.