Question: can anybody help me to solve this differential equations?

Eq[1] := .1*(diff(r(rho), rho))^5*r(rho)^4*sin(theta(rho))+(diff(r(rho), rho))^3*cos(theta(rho))^2*sin(theta(rho))*(r(rho)^4-.1*rho^4)+(diff(r(rho), rho))*rho^4*cos(theta(rho))^4*sin(theta(rho))+(r(rho)^2*rho^2*(diff(r(rho), rho))^4*cos(theta(rho))-rho^4*cos(theta(rho))^5+.1*r(rho)^4*(diff(r(rho), rho))^4-.1*r(rho)^2*rho^2*cos(theta(rho))^5)*(diff(theta(rho), rho))*r(rho)

 

Eq[2] := p*(diff(r(rho), rho))*cos(theta(rho))^3*rho-(diff(r(rho), rho))^4*r(rho)^2*sin(theta(rho))+rho^2*cos(theta(rho))^4*sin(theta(rho))-.1*r(rho)^4*(diff(r(rho), rho))^4*sin(theta(rho))+.1*cos(theta(rho))^4*sin(theta(rho))*r(rho)^2

 


ICs := r(1) = 1., theta(1) = 1.4

parameters := {P = 4}

for i to 2 do eq[i] := subs(parameters, Eq[i]) end do

eqs := eq[1], eq[2]

vars := r(rho), theta(rho)

sol := dsolve({ICs, eqs}, {vars}, type = numeric, output = array([seq((1/20)*i, i = 20 .. 40)]))

Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)
Error, (in DEtools/convertsys) unable to convert to an explicit first-order system

 

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