Problem 3: Vectors
Given A = -2i + j + k and B = 3i - j + k, determine C = A × B
Problem 4: Matrices and Trig Identities
A standard rotation matrix (R) around an angle θ is defined as:
R = (cosθ -sinθ
sinθ cosθ)
Show that R² represents a rotation through an angle 2θ. [HINT: After you execute the matrix multiplication, you will need to use trig identities to prove R² is a rotation about 2θ].