$$$2\cdot \left\langle - \frac{\cos{\left(t \right)}}{2}, 0, - \frac{\sin{\left(t \right)}}{2}\right\rangle$$$
Your Input
Calculate $$$2\cdot \left\langle - \frac{\cos{\left(t \right)}}{2}, 0, - \frac{\sin{\left(t \right)}}{2}\right\rangle$$$.
Solution
Multiply each coordinate of the vector by the scalar:
$$${\color{SaddleBrown}\left(2\right)}\cdot \left\langle - \frac{\cos{\left(t \right)}}{2}, 0, - \frac{\sin{\left(t \right)}}{2}\right\rangle = \left\langle {\color{SaddleBrown}\left(2\right)}\cdot \left(- \frac{\cos{\left(t \right)}}{2}\right), {\color{SaddleBrown}\left(2\right)}\cdot \left(0\right), {\color{SaddleBrown}\left(2\right)}\cdot \left(- \frac{\sin{\left(t \right)}}{2}\right)\right\rangle = \left\langle - \cos{\left(t \right)}, 0, - \sin{\left(t \right)}\right\rangle$$$
Answer
$$$2\cdot \left\langle - \frac{\cos{\left(t \right)}}{2}, 0, - \frac{\sin{\left(t \right)}}{2}\right\rangle = \left\langle - \cos{\left(t \right)}, 0, - \sin{\left(t \right)}\right\rangle$$$A