Question:
If $\overrightarrow{\mathrm{a}}=(\hat{\mathrm{i}}+2 \hat{\mathrm{j}}-3 \hat{\mathrm{k}})$ and $\overrightarrow{\mathrm{b}}=(3 \hat{\mathrm{i}}-\hat{\mathrm{j}}+2 \hat{\mathrm{k}})$ then calculate the angle between $(2 \overrightarrow{\mathrm{a}}+\overrightarrow{\mathrm{b}})$ and $(\overrightarrow{\mathrm{a}}+2 \overrightarrow{\mathrm{b}})$.
Solution:
