Question

http://gyazo.com/1a92dfd07c05de9eac4f6a6d48b603c7 question in pic link

Answer 1

\[\sqrt{a^2+b^2}\] is the absolute value of \(a+bi\)
check each one

Answer 2

or just eyeball it
you have to square one of the numbers and add, so it is pretty clearly not the first three

Answer 3

so its D?