# Thread: how to find an equation given something

1. ## how to find an equation given something

if i= square root of -1, then -4i (6i ) is...

2. Let's review the properties of i:

$
i = sqrt (-1)
$

$
i^2 = -1
$

$
i^3 = -i
$

$
i^4 = 1
$

each set of i iterates in this fashion which means
$i^5 = sqrt(-1)$