"1^2" = 1 to the 2nd power.
2006-10-03 17:48:40 · 4 answers · asked by luke88 1 in Education & Reference ➔ Homework Help
This is just the difference of two squares (remember
x^2 - y^2 = (x+y)(x-y) ?).
(1-2i)^2 - (1+2i)^2 = (1-2i+1+2i)(1-2i-1-2i)
= (2)(-4i)
= -8i
2006-10-03 18:02:09 · answer #1 · answered by wild_turkey_willie 5 · 0⤊ 0⤋
8
2006-10-04 00:54:09 · answer #2 · answered by Timmy 2 · 0⤊ 0⤋
First, we FOIL both terms.
(1 - 2i -2i + 4i^2) - (1 + 2i + 2i + 4i^2)
Then, substitute i^2 = -1.
(1 - 4i - 4) - (1 + 4i - 4)
Combine like terms.
(-3 - 4i) - (-3 + 4i)
Distribute the negative sign.
-3 - 4i + 3 - 4i
Combine like terms.
- 8i
2006-10-04 00:53:41 · answer #3 · answered by lintile 2 · 2⤊ 1⤋
(1-2i)^2-(1+2i)^2
(1-2i)(1-2i)-(1+2i))(1+2i)
1-2i-2i+4i - 1+2i+2i+4i
1-4i+4i - 1+4i+4i
1 - 1+8i
8i
i=8
2006-10-04 01:01:31 · answer #4 · answered by Jessica K 2 · 0⤊ 0⤋