On Thu, 26 Nov 2009, Julien Martin wrote:
< Hello,
< I am trying to solve the following equation:
<
< sum(4500*(1+r)^-i, i, 1, inf)=60000;
< solve(%, r);
<
< And I only get a pair of empty brackets as a result...
< Any clue?
< Julien.
<
<
Julien,
You'll need to tell Maxima to simplify the sum:
(%i2) sum(4500*(1+r)^-i, i, 1, inf)=60000,simpsum;
Is abs(r+1)-1 positive, negative, or zero?
p;
(%o2) 4500/((r+1)*(1-1/(r+1))) = 60000
(%i3) solve(%,r);
(%o3) [r = 3/40]
Leo
--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.