(1+i)^n+(1-i)^n=
2007-03-22 01:59:33 · 4 answers · asked by good_girl_alexia_snape 2 in Education & Reference ➔ Homework Help
intrest to know what the sum equals, not the n
2007-03-22 02:06:51 · update #1
i*i is = -1
2007-03-22 02:08:50 · update #2
Haven't learn yet the binomial theorem
2007-03-22 02:29:16 · update #3
I'm sorry, I don't have much time right now, so I haven't thought this through, but hopefully, this is the start to the right track of thinking... And hopefully you're already learned the binomial theorem...
The general term in the expansion of: (1+i)^n = nCr (1)^(n-r) (i)^r = nCr (i)^r
[Because "1" to the power of anything is just "1"]
The general term in the expansion of:
(1-i)^n = nCr (1)^(n-r) (-i)^r = nCr (-i)^r = nCr (-1)^r (i)^r
Remembe, these are just the general terms... the actual expansion of (1-i)^n, for example is the sum of "nCr (-1)^r (i)^r" for r = 0, 1, 2, ... n. Now, don't get discouraged... Remember that "i" is mod 4 - in other words, there are only 4 choices that the powers of "i" can be... then they repeat (i, -1, -i, 1) And, also remember that the powers of "-1" are only -1 and 1...
Mmmm... I'm sorry I don't have time to think this through, but I *think* that this is the right starting point.
Good luck!!!
2007-03-22 02:24:45 · answer #1 · answered by Anonymous · 0⤊ 0⤋
what does n equal?! revise your question and i'll come back and edit my answer.
2007-03-22 09:03:54 · answer #2 · answered by squirrelman9014 3 · 1⤊ 0⤋
what does i and n equal, change this and i can answer
2007-03-22 09:07:29 · answer #3 · answered by xswise1 2 · 0⤊ 1⤋
homework.com
2007-03-22 09:51:02 · answer #4 · answered by mncltrr 3 · 0⤊ 0⤋