I have the following problem:
I use the solve function to solve a system of 3 nonlinear equations with 3 unknowns. Due to the nonlinearity of the problem I get several solutions. I want the values of the 3 unknowns though to lie in a certain range or be positive. I really can not figure out the instructions to Mathematica to receive as an output only the values of the variables, which lie in a prespecified range. Can you help me out ?