How to use "Solve" to get only real number solutions?

*To*: mathgroup at smc.vnet.net*Subject*: [mg55132] How to use "Solve" to get only real number solutions?*From*: "PengYu.UT at gmail.com" <PengYu.UT at gmail.com>*Date*: Sun, 13 Mar 2005 04:57:54 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi All For example I have the following function and I want to find the solution of the quation shown below. But Mathematica showns not only real number solutions. Do you know how to restrict the solutions to only real numbers. Thanks! Best wishes, Peng intensity[x_, Î´_, p_, Î»_] := 1/4 + (2*Cos[(Pi*x)/100])/Pi + (4*Cos[(Pi*x)/100]^2)/Pi^2 - (2*Cos[(3*Pi*x)/100])/(3*Pi) - (8*Cos[(Pi*x)/100]*Cos[(3*Pi*x)/100])/(3*Pi^2) + (4*Cos[(3*Pi*x)/100]^2)/(9*Pi^2) Solve[intensity[x, 0, 200, 50] == 0.3*(1/4 + 32/(9*Pi^2) + (4*Sqrt[2])/(3*Pi)), x]