eq3 = k== (x./(1-x))*sqrt((2*px)./(2+x)); **
but now it says: Warning: Solutions are valid under the following conditions: (z1 == 1 | signIm(((z1 - 1)*1i)/z1) == -1) & z1^3
- 4375*z1^2 - 3*z1 + 2 == 0 & z1 ~= 1 & z1 ~= -2. To include parameters and conditions in the solution,
specify the 'ReturnConditions' value as 'true'.
> In solve>warnIfParams (line 482)
In solve (line 357)