Scalar and vector products of two vectors. Given two vectors $\mathbf{a}=3 \hat{\mathbf{x}}+4 \hat{y}-5 \hat{\mathbf{z}}$ and $\mathbf{b}=-\hat{\mathbf{x}}+2 \hat{\mathbf{y}}+6 \hat{\mathbf{z}}$, calculate by
vector methods:
(a) The length of each Ans, $a=\sqrt{50} ; b=\sqrt{41}$.
(b) The scalar product a \cdot b Ans. $-25$.
(c) The included angle between them Ans. $123.5^{\circ}$.
(d) The direction cosines for each
(e) The vector sum and difference $a+b$ and $a-b$