Question

Write the complex number `(3+10i)^2` in standard form?

Answer 1

You can write it as:
`(3+10i)(3+10i)=` multiply the two brackets:
`=9+30i+30i+100i^2=`

But `i^2=(sqrt(-1))^2=-1`
so:
`=9+60i-100=-91+60i`