# Question:System of 4 non-linear equations, fsolve

## Question:System of 4 non-linear equations, fsolve

Maple 2023

Hi,

Im trying to solve a system of 4 non-linear equations using the fsolve function. When i compute the command i seemingly dont get an answer to the system. Maple only prompts the command itself, can any of you locate my mistake or give any input on how to solve the issue.

My code is as follows:

restart;
r__C := 400;
r__D := 600;
r__E := 800;
a := 100;
p := 0.7;
q := Pi*a^2*p;
h__eq := 0.9*h__1*(E__1/E__2)^(1/3);
R__Ceq := sqrt(h__eq^2 + r__C^2);
R__C := sqrt(r__C^2 + h__1);
R__Deq := sqrt(h__eq^2 + r__D^2);
R__D := sqrt(r__D^2 + h__1);
R__Eeq := sqrt(h__eq^2 + r__E^2);
R__E := sqrt(r__C^2 + h__1);

eqC := 174.5*10^(-3) = q*(1 + nu)/(2*Pi*E__2*R__Ceq)*(2*(1 - nu) + h__eq^2/R__Ceq^2) + q*(1 + nu)/(2*Pi*E__1*r__C)*(2*(1 - nu) + 0) - q*(1 + nu)/(2*Pi*E__1*R__C)*(2*(1 - nu) + h__1^2/R__C^2);
eqD := 151.7*10^(-3) = q*(1 + nu)/(2*Pi*E__2*R__Deq)*(2*(1 - nu) + h__eq^2/R__Deq^2) + q*(1 + nu)/(2*Pi*E__1*r__D)*(2*(1 - nu) + 0) - q*(1 + nu)/(2*Pi*E__1*R__D)*(2*(1 - nu) + h__1^2/R__D^2);
eqE := 133.2*10^(-3) = q*(1 + nu)/(2*Pi*E__2*R__Eeq)*(2*(1 - nu) + h__eq^2/R__Eeq^2) + q*(1 + nu)/(2*Pi*E__1*r__E)*(2*(1 - nu) + 0) - q*(1 + nu)/(2*Pi*E__1*R__E)*(2*(1 - nu) + h__1^2/R__E^2);
eqA := 401.7*10^(-3) = 2*q*a*(-nu^2 + 1)*(sqrt(1 + (h__eq/a)^2) - h__eq/a)/E__2 + 2*(-nu^2 + 1)*q*a/E__1 - 2*q*a*(-nu^2 + 1)*(sqrt(1 + (h__1/a)^2) - h__1/a)/E__1;

fsolve({eqA, eqC, eqD, eqE}, {E__1, E__2, h__1, nu}, {E__1 = 0 .. 5000, E__2 = 0 .. 5000, h__1 = 0 .. 1000, nu = 0 .. 0.5});

Picture for refference:

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