Obtain scalar product in terms of Cartesian component of vectors.
The angle between the two vectors $\overrightarrow A = 5\hat i + 5\hat j$ and $\overrightarrow B = 5\hat i - 5\hat j$ will be ....... $^o$
If $\overrightarrow A \times \overrightarrow B=\overrightarrow B \times \overrightarrow A$ then the angle between $\overrightarrow A$ and $\overrightarrow B$ is