Question

(1 + 4i)^2

Solve please?

Answer 1

-15 + 8i

Explanation:

(1 + 4i)²

(1 + 4i) (1 + 4i)

FOIL - first -- outer -- inner -- last

F -- 1 x 1 = 1

O -- 1 x 4i = 4i

I -- 4i x 1 = 4i

L -- 4i x 4i = 16i²

combine terms

1 + 4i + 4i + 16i²

simplify

1 + 8i + 16i²

(i² = -1)

simplify further

1 + 8i + (16)(-1)

1 + 8i - 16

-15 + 8i