MATLAB: Solve function with equations and inequations

Question

Dear all, I'm using the solve function to determine a function out of several conditions (location of maxima,fixed points, etc.). I thought about using the solve function but struggle with using equations and inequations simultaneously.

syms x_1 x_2 x_3 x_4 x_max
    eqns= [3* x_1 * (x_max)^2 + 2 * x_2 * x_max + x_3 ==0 , ...
           1/4 * 100^4 * x_1 + 1/3 * 100^3 * x_2 + 1/2 * 100^2 * x_3 + 100 * x_4 == 1, ...
           5^3 * x_1 + 5^2 * x_2 + 5 *x_3 + x_4 ==0 , ...
           100^3 * x_1 + 100^2 * x_2 + 100 * x_3 + x_4 > 2.3 ];
    S =solve(eqns, [x_1 x_2 x_3 x_4 x_max]);

I now would like to insert any x_max value to receive specific values for every parameter. How can I implement this, or first: How can I solve these functions? Does anyone has an idea?

Best, Jan

Answer 1

Thank you very much for all your comments!

I experienced that it is much easier onlin in "Wolfram alfa" or "dcode".

Best, Jan