# Homework Help: What is the sine of i (initial value prob)

1. Feb 10, 2012

### fufufu

what is the sine of "i" (initial value prob)

1. The problem statement, all variables and given/known data
What is the sine or cosine of i?
does it make sense to ask what sine of root (-1) is?

im asking because its from 2nd order DE: t^2y'' - ty' + y = 0.......y(1) = 1 y'(1) = 1

when i rearrranged and determined omega it ended up being i.. is that wrong??

(omega squared = -(1/t) so omega = i)

?

please help...thanks

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 10, 2012

### tiny-tim

sinx = (eix - e-ix)/2

so sini = … ?

3. Feb 10, 2012

### LCKurtz

Re: what is the sine of "i" (initial value prob)

You didn't show any work and I don't know what ω is that you are talking about nor what the sine or cosine functions have to do with this problem, let alone the sine of i.

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