Assume a = 1. If not set b = b/a, etc. Now use (1) uniroot > f <- function(x) b + c/(1+x) + d/(1+x)^2 - 1 - x > uniroot(f, 0:1) $root [1] 0.8392679
$f.root [1] 3.049818e-05 $iter [1] 3 $estim.prec [1] 6.103516e-05 or multiply through by 1+x and subtract 1 from both sides giving x = b + c/(1+x) + d/(1+x)^2 - 1 and iterate that. > a <- b <- c <- d <- 1 > x <- 0 > for(i in 1:25) { + x <- b + c/(1+x) + d/(1+x)^2 - 1 + print(x) + } [1] 2 [1] 0.4444444 [1] 1.171598 [1] 0.6725419 [1] 0.9553676 [1] 0.7729558 [1] 0.8821595 [1] 0.8135892 [1] 0.8554268 [1] 0.829437 [1] 0.8454056 [1] 0.835527 [1] 0.8416126 [1] 0.837854 [1] 0.8401717 [1] 0.838741 [1] 0.8396236 [1] 0.839079 [1] 0.839415 [1] 0.8392076 [1] 0.8393356 [1] 0.8392566 [1] 0.8393053 [1] 0.8392753 [1] 0.8392938 On Mon, Dec 1, 2008 at 9:47 PM, RON70 <[EMAIL PROTECTED]> wrote: > > I need to solve a equation like this : > > a = b/(1+x) + c/(1+x)^2 + d/(1+x)^3 > > where a,b,c,d are known constant. Is there any R-way to do that? > > Thanks in advance > -- > View this message in context: > http://www.nabble.com/How-to-solve-following-equation--tp20785063p20785063.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.