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1. I have been given

1/2pi*[ (2pi*(-1)^n)/-i*n)]= (i*(-1)^n)/n

However I just get the 2pi cancelling each other out and getting

((-1)^n)/(i*n)

This is surely just an error in the sheet right or am I missing something?
2. (Original post by anonstudent1)
I have been given

1/2pi*[ (2pi*(-1)^n)/-i*n)]= (i*(-1)^n)/n

However I just get the 2pi cancelling each other out and getting

((-1)^n)/(i*n)

This is surely just an error in the sheet right or am I missing something?
What're you trying to find??

Are you trying to rearrange the first on into the second?
3. (Original post by TheIrrational)
What're you trying to find??

Are you trying to rearrange the first on into the second?

1/2pi*[ (2pi*(-1)^n)/-i*n)] Is what I have been given. The answer on the r.h.s of the equals sign is the answer. But I don't see how its the answer.
4. Do you have

or

5. (Original post by TenOfThem)
Do you have

or

the bottom line is i*n, not to the power.
http://math.ucsd.edu/~lni/math140/HW..._solutions.pdf

I don't understand how they have gotten from the 4th line to the 5th
6. (Original post by anonstudent1)
the bottom line is i*n, not to the power.
http://math.ucsd.edu/~lni/math140/HW..._solutions.pdf

I don't understand how they have gotten from the 4th line to the 5th
So you have

I assume that they multiplied numerator and denominator by i

7. (Original post by TenOfThem)
So you have

I assume that they multiplied numerator and denominator by i

(i(-1)^n)/n

If i multiplied the numerator and denominator by i, I get

(i((-1)^n))/((-i^2)n)
8. (Original post by anonstudent1)

(i(-1)^n)/n

If i multiplied the numerator and denominator by i, I get

(i((-1)^n))/((-i^2)n)
I assume that you know what is

So that you know what - is
9. (Original post by TenOfThem)
I assume that you know what is

So that you know what - is
Well I just found out it equals -1 and it makes complete sense now. I didn't think you could just square it like another number before for some reason. Certainly makes my life easier, anyway thanks for your help!
10. (Original post by anonstudent1)
Well I just found out it equals -1 and it makes complete sense now. I didn't think you could just square it like another number before for some reason. Certainly makes my life easier, anyway thanks for your help!
Did you not know that

Are you self teaching?
11. (Original post by TenOfThem)
Did you not know that

Are you self teaching?
I do, I've known that for ages! Its just for some reason I didn't think you could just square it like another number and then it would just equal minus 1.

And well i rarely go to lectures... so in a way lol

I definitely should have cottoned on earlier, but when i've looked at something for so long and i'm sure they've just made a typo, i can get stuck on ridiculousy easy things.
12. (Original post by anonstudent1)
I do, I've known that for ages! Its just for some reason I didn't think you could just square it like another number and then it would just equal minus 1.

And well i rarely go to lectures... so in a way lol

I definitely should have cottoned on earlier, but when i've looked at something for so long and i'm sure they've just made a typo, i can get stuck on ridiculousy easy things.
Fair enough

We usually rationalise the denominator so anything with i in the denominator will need to be * by something
13. (Original post by TenOfThem)
Fair enough

We usually rationalise the denominator so anything with i in the denominator will need to be * by something
Thank you , ill be sure to apply that in the future!

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