Question

Write the complex number `(2+3i)^2` in standard form?

Answer 1

I found: `-5+12i`

Explanation:

You can write it as:
`(2+3i)(2+3i)=`
multiply:
`=4+6i+6i+9i^2=`
but `i^2=(-1)^2=-1`
so:
`4+12i-9=-5+12i`