Brush up on your knowledge of working with vectors, including how to evaluate scalar product and determine the angle between two vectors ...

OABC is a parallelogram. \(\overrightarrow{OA}\) is represented by the vector \(\mathbf{a}\) and \(\overrightarrow{OC}\) is represented by the vector \(\mathbf{c}\). M is the mid-point of BC and N is ...