help please with math
2007-11-20 13:17:30 · 4 answers · asked by La ilaha il Allah 2 in Science & Mathematics ➔ Mathematics
I know the above gave the answers but just remember two things when doing such problems..
i^1= sqrt(-i)
i^2 = -1
i^3 = -i
USE foil ..
(a+b)^2
a^2 + 2(a)(b) + b^2
2007-11-20 13:27:18 · answer #1 · answered by Hi 2 · 0⤊ 1⤋
First: eliminate parenthesis - use the Foil method.
(5+3i)(5+3i)
(5)(5)+(5)(3i)+(3i)(5)+(3i)(3i)
25 + 15i + 15i + 9i^2
Sec: combine "like" terms - combine the middle terms.
25 + 30i + 9i^2
Third: i^2 becomes (-1).
25 + 30i + 9(-1)
25 + 30i + (-9)
25 + 30i - 9
25 - 9 + 30i
16 + 30i
2007-11-20 14:42:38 · answer #2 · answered by ♪♥Annie♥♪ 6 · 0⤊ 0⤋
answer= 16+30i
5+3i(5+3i)= 25+15i+15i+9i^2= 25+30i-9= 16+30i
2007-11-20 13:23:34 · answer #3 · answered by Anonymous · 0⤊ 1⤋
Just use the FOIL rule and the fact that i² = -1.
You get 34 + 30i
2007-11-20 13:20:28 · answer #4 · answered by steiner1745 7 · 0⤊ 1⤋