Question #19db9

1 Answer
Nov 19, 2017

(2+3i)^2=-5+12i

Explanation:

Laws:
(a+b)^2=a^2+2*a*b+b^2
(a*b)^2=a^2*b^2
i=sqrt(-1) => i^2=(sqrt(-1))^2=-1


(2+3i)^2=
=2^2+2*2*3i+(3i)^2=
=4+12i+(3^2*i^2)=
=4+12i+(9*(-1))=
=4+12i+(-9)=
=-5+12i