Re: yield to maturity
- To: mathgroup at smc.vnet.net
- Subject: [mg41743] Re: yield to maturity
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Tue, 3 Jun 2003 07:13:27 -0400 (EDT)
- Organization: The University of Western Australia
- References: <bbf34j$q2i$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <bbf34j$q2i$1 at smc.vnet.net>,
"Jonathan Mann" <mtheory at msn.com> wrote:
> I need to solve for r in an equation of the form:
>
> Sum[I/(1+r)^t, {t,1,n}] + M/(1+r)^n ]==P
>
> For example's sake, let's say:
>
> Solve[ Sum[ 45/(1+r)^t ,{t,1,5}] + 1000/(1+r)^5 == 913, r]
>
> This isn't working out too well.
Actually, it is working perfectly! It is giving you exact
representations of the 5 solutions to this equation. However, for r > 0,
you can use
Experimental`CylindricalAlgebraicDecomposition[
Sum[45/(r + 1)^t, {t, 1, 5}] + 1000/(r + 1)^5 == 913 && r > 0, {r}]
which gives an _exact_ representation of the solution you are after. If
you apply N to this you get
N[%]
r == 0.06599124150108003
Cheers,
Paul
--
Paul Abbott Phone: +61 8 9380 2734
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