A bit pedestrian, but you might try pf <- function(x){5/((1+x)^1) + 5/((1+x)^2) + 5/((1+x)^3) + 105/((1+x)^4) -105} uniroot(pf,c(-10,10)) curve(pf, c(-10,10)) require(pracma) tryn <- newton(pf, 0) tryn pf(0) pf(0.03634399) yc <- c(-105, 5,5,5,105) rooty <- polyroot(yc) rooty rootx <- 1/rooty - 1 rootx
There are lots of rootfinders, and the histoRicalg project (https://gitlab.com/nashjc/histoRicalg) that is supported by the R Consortium to look into older codes has quite a bit on rootfinders. JN On 2018-11-20 7:09 a.m., Engin Yılmaz wrote: > > > Dea(R) > I try to solve one equation but this program did not give me real roots > for example > yacas("Solve( 5/((1+x)^1) + 5/((1+x)^2) + 5/((1+x)^3) + 105/((1+x)^4) -105 > ==0, x)") > gave me following results > How can I find real roots? > > expression(list(x == complex_cartesian((1/42 - ((1/63 - > ((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3)))/21 - -2/21)/(4 * root(((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3) - 1/63)^2/4 + 1, 2)))/2 - 1, root(4 * > (((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3) - 1/63)/2 + root(((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3) - 1/63)^2/4 + 1, 2)) - (((1/63 - > ((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3)))/21 - -2/21)/(4 * root(((root(7339451281/3087580356, > 2) - 4535/71442)^(1/3) - (4535/71442 + root(7339451281/3087580356, > 2))^(1/3) - 1/63)^2/4 + 1, 2)) - 1/42)^2, 2)/2),...more > > > > > Engin Yılmaz <ispanyol...@gmail.com>, 20 Kas 2018 Sal, 12:53 tarihinde şunu > yazdı: > >> Thanks a lot! >> >> Berend Hasselman <b...@xs4all.nl>, 20 Kas 2018 Sal, 12:02 tarihinde şunu >> yazdı: >> >>> >>> >>> R package Ryacas may be what you want. >>> >>> Berend >>> >>> >>>> On 20 Nov 2018, at 09:42, Engin Yılmaz <ispanyol...@gmail.com> wrote: >>>> >>>> Dea(R) >>>> >>>> Do you know any system solver in R ? >>>> >>>> For example, in matlab, is very easy >>>> >>>> syms a b c x eqn = a*x^2 + b*x + c == 0; sol = solve(eqn) >>>> >>>> How can I find this type code in R (or directly solver)? >>>> >>>> *Since(R)ely* >>>> Engin YILMAZ >>>> >>>> [[alternative HTML version deleted]] >>>> >>>> ______________________________________________ >>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>>> 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. >>> >>> >> >> -- >> *Saygılarımla* >> Engin YILMAZ >> > > > -- > *Saygılarımla* > Engin YILMAZ > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.