Solución

Apartado a

Sea α\alpha el ángulo formado por v\bold{v} e i\bold{i}:

cosα=vivi=2,3,31,0,022+32+321=222\begin{aligned} cos\alpha &= \frac{\bold{v}\cdot\bold{i}}{\|\bold{v}\|\cdot\|\bold{i}\|}\\ &= \frac{\lang 2,3,3\rang\cdot\lang 1,0,0\rang}{\sqrt{2^2+3^2+3^2}\sqrt{1}}\\ &= \frac{2}{\sqrt{22}} \end{aligned} α=arccos2221.130rad\alpha = arccos\frac{2}{\sqrt{22}} \approx 1.130 rad

Apartado b

Supongamos que θ\theta representa el ángulo formado por v\bold{v} y j\bold{j}:

cosβ=vjvj=2,3,30,1,022+32+321=322\begin{aligned} cos\beta &= \frac{\bold{v}\cdot\bold{j}}{\|\bold{v}\|\cdot\|\bold{j}\|}\\ &= \frac{\lang 2,3,3\rang\cdot\lang 0,1,0\rang}{\sqrt{2^2+3^2+3^2}\sqrt{1}}\\ &= \frac{3}{\sqrt{22}} \end{aligned} β=arccos3220.877rad\beta = arccos\frac{3}{\sqrt{22}} \approx 0.877 rad

Apartado c

Sea γ\gamma el ángulo formado por v\bold{v} y k\bold{k}:

cosβ=vkvk=2,3,30,0,122+32+321=322\begin{aligned} cos\beta &= \frac{\bold{v}\cdot\bold{k}}{\|\bold{v}\|\cdot\|\bold{k}\|}\\ &= \frac{\lang 2,3,3\rang\cdot\lang 0,0,1\rang}{\sqrt{2^2+3^2+3^2}\sqrt{1}}\\ &= \frac{3}{\sqrt{22}} \end{aligned} γ=arccos3220.877rad\gamma = arccos\frac{3}{\sqrt{22}} \approx 0.877 rad