Multiply (3-2i)2=32-2(3)(2i)+(2i)2

gr.11 student...Angie

Hi Angie,

You are correct so far. 32 = 9 and 2(3)(2) = 12 so

(3-2i)2=32-2(3)(2i)+(2i)2 = 9 + 12 i + (2i)2

But (2i)2 = (2i)(2i) = (2)(2)(i)(i) = 4 i2 and i2 = -1. Thus

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

Cheers,
Penny
Go to Math Central