On 23/07/2012 2:46 PM, Diviya Smith wrote: > Hi there, > > I would like to solve the following equation in R to estimate 'a'. I have > the amp, d, x and y. > > amp*y^2 = 2*a*(1-a)*(-a*d+(1-a)*x)^2 > > test data: > amp = 0.2370 y= > 0.0233 d= > 0.002 x= > 0.091 > Can anyone suggest how I can set this up? See ?polyroot. Duncan Murdoch