3.- Dados los siguientes vectores:
\(\vec{a}\)= \(4i-3j+k\) y
\(\vec{b}\)=\(-i+j+4k\).
Calcule \(\vec{a}\)\(\cdot\)\(\vec{b}\) y \(\vec{a}\) x \(\vec{b}\).
\(\vec{a}\)\(\cdot\)\(\vec{b}\) = \(\left(4\right)\left(-1\right)i+\left(-3\right)\left(1\right)j+\left(1\right)\left(4\right)k\)= \(-3\)
\(\vec{a}\) x \(\vec{b}\)= \(i\left(-3\right)\left(4\right)-\left(1\right)\left(1\right)-j\left[\left(4\right)\left(4\right)-\left(1\right)\left(-1\right)\right]+k\left(4\right)\left(1\right)-\left(-3\right)\left(-1\right)\)= \(-13i\ -17j+k\)