How do you write (2+3i)^2 in standard form?

1 Answer
Dec 14, 2015

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

Explanation:

Rewrite the expression as

(2+3i)^2 = (2+3i)(2+3i)

Expand by multiplying the expression to get

(4+ 6i +6i +9i^2)

Combine like terms

(4 + 12 i + 9i^2)

Replace i^1= -1 , this is be definition if imaginary number

(4 + 12 i + 9 *(-1)) => 4 - 9 + 12i => -5 + 12i

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