# Complex Cross Product/Examples/3-i cross 2+5i

## Example of Complex Cross Product

Let:

$z_1 = 3 - i$
$z_2 = 2 + 5 i$

Then:

$z_1 \times z_2 = 17$

where $\times$ denotes (complex) cross product.

## Proof

 $\ds z_1 \circ z_2$ $=$ $\ds \paren {3 - i} \times \paren {2 + 5 i}$ $\ds$ $=$ $\ds 3 \times \paren 5 - \paren {-1} \times 2$ Definition 1 of Complex Cross Product $\ds$ $=$ $\ds 15 - \paren {-2}$ $\ds$ $=$ $\ds 17$

$\blacksquare$