Question

Let a=3i-2j+5k & b=i+3j+4k. Find vector a*b & a.b

Answer 1

$$\bold{a\cdot b}=3\cdot 1-2\cdot 3+5\cdot 4=17$$

$$\bold{a\times b}=\begin{vmatrix} i & j & k\\ 3 & -2 & 5\\ 1 & 3 & 4\\ \end{vmatrix}$$

$$\bold{a\times b}=-23\bold{i}-7\bold{j}+11\bold{k}$$