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Question: Problem in solving a differential equation

Question:Problem in solving a differential equation

pooyan1990 35 Maple 2019
syntax dsolve differential-equations user-error
April 05 2023
0

I receive the following error when I run maple to solve a diff equation.
Thank you in advance for your help.

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eq1:=A__n=[X__n+[(C-z)*(tan(theta1)+tan(theta2))]] * [B + (2*(C-z)*tan(theta3))];
eq2:=P__n=[2*(X__n+B)] + 2 * (C-z) * [(tan(theta1)+tan(theta2)) + (2*tan(theta3))];
eq3:=gamma - [cu*(P__n/A__n)] = diff(sigma__v(z),z);
eq4:=subs([eq1,eq2],eq3);
ics:=sigma__v(0)=sigma__s;
sol:=simplify(dsolve(([eq4,ics]), sigma__v(z)));
NULL

A__n = [X__n+[(C-z)*(tan(theta1)+tan(theta2))]]*[B+2*(C-z)*tan(theta3)]

  

P__n = [2*X__n+2*B]+2*(C-z)*[tan(theta1)+tan(theta2)+2*tan(theta3)]

  

gamma+[-cu*P__n/A__n] = diff(sigma__v(z), z)

  

gamma+[-cu*([2*X__n+2*B]+2*(C-z)*[tan(theta1)+tan(theta2)+2*tan(theta3)])/([X__n+[(C-z)*(tan(theta1)+tan(theta2))]]*[B+2*(C-z)*tan(theta3)])] = diff(sigma__v(z), z)

  

sigma__v(0) = sigma__s

  

Error, (in PDEtools/NumerDenom) invalid input: `PDEtools/NumerDenom` expects its 1st argument, ee, to be of type algebraic, but received [tan(theta1)+tan(theta2)+2*tan(theta3)]

  
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