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## #1 Re: Help Me ! » First order differential equation » 2012-10-09 19:23:51

Okay, but the result of this equation is  that y(t) is a complex function ( y² = sqrt(-(t²+1))/t ). Can this be the right answer?

## #2 Re: Help Me ! » First order differential equation » 2012-10-09 19:03:50

How exactly do you separate?

## #3 Help Me ! » First order differential equation » 2012-10-09 16:30:38

yago.dorea
Replies: 5

I want to solve the following ODE:

(1 + t²)y' = ty(1 + y²)   where y = y(t).

If I try to solve it by separation, I get complex roots, but I'm not trained yet to deal with them.

What should I do?

## #4 Re: Help Me ! » Fibonacci's determinant » 2012-09-09 23:07:44

I'm glad I found this forum. I am being amazed by some topics in the "Dark Discussions at Cafe Infinity" section. Mainly one article about the Vandermonde Determinant.

## #5 Re: Help Me ! » Fibonacci's determinant » 2012-09-09 21:46:56

Ah I got it, you start from the beggining, I was doing the cofactors of the last terms... Thank you!

## #6 Help Me ! » Fibonacci's determinant » 2012-09-09 20:57:34

yago.dorea
Replies: 5

Hello, I want to prove that the determinant of Fibonacci's nxn tridiagonal matrix is equal to the (n+1)th term of the Fibonacci sequence.

I'm trying to do it by induction, stating that det(F(n)) = det(F(n-1)) + det(F(n-2)) (yeah I don't know how to use LaTex)
but I don't know how to prove that the minor M(n, n-1)(F(n)) = det(F(n-2))

Thanks.