# Question:How to return y=2+0*I as y = 2

## Question:How to return y=2+0*I as y = 2

Maple

I want to  return {x = 0., y = 1.158748796 + 0. I}  as  {x = 0., y = 1.158748796 }.  The solution is coming from:

soln3:= fsolve({b1, b2}, {x = 0 .. infinity, y = 0 .. infinity});

and the second solution is coming from:
soln4:= fsolve({b1, b2}, {x = -infinity ..0, y = -infinity .. 0});

See my code below

restart:

Procedure

doCalc:= proc( xi )

# Import Packages
uses ArrayTools, Student:-Calculus1, LinearAlgebra,
ListTools, RootFinding, plots, ListTools:
local gamma__1:= .1093,
alpha__3:= -0.1104e-2,
k__1:= 6*10^(-12),
d:= 0.2e-3,
theta0:= 0.0001,
eta__1:= 0.240e-1,
alpha:= 1-alpha__3^2/(gamma__1*eta__1),
c:= alpha__3*xi*alpha/(eta__1*(4*k__1*q^2/d^2-alpha__3*xi/eta__1)),
theta_init:= theta0*sin(Pi*z/d),
n:= 30,
g, f, b1, b2, qstar, OddAsymptotes, ModifiedOddAsym,
qstarTemporary, indexOfqstar2, qstar2, AreThereComplexRoots,
soln1, soln2, qcomplex1, qcomplex2, gg, qq, m, pp, j, i,
AllAsymptotes, p, Efun, b, aa, F, A, B, Ainv, r, theta_sol, v, Vfun, v_sol,minp,nstar,
soln3, soln4, Imagroot1, Imagroot2;

# Assign g for q and plot g, Set q as a complex and Compute the Special Asymptotes

g:= q-(1-alpha)*tan(q)+ c*tan(q):
f:= subs(q = x+I*y, g):
b1:= evalc(Re(f)) = 0:
b2:= y-(1-alpha)*tanh(y) -(alpha__3*xi*alpha/(eta__1*(4*k__1*y^2/d^2+alpha__3*xi/eta__1)))*tanh(y) = 0:
qstar:= (fsolve(1/c = 0, q = 0 .. infinity)):
OddAsymptotes:= Vector[row]([seq(evalf(1/2*(2*j + 1)*Pi), j = 0 .. n)]);

# Compute Odd asymptote

ModifiedOddAsym:= abs(`-`~(OddAsymptotes, qstar));
qstarTemporary:= min(ModifiedOddAsym);
indexOfqstar2:= SearchAll(qstarTemporary, ModifiedOddAsym);
qstar2:= OddAsymptotes(indexOfqstar2);

# Compute complex roots

AreThereComplexRoots:= type(true, 'truefalse');
try
soln1:= fsolve({b1, b2}, {x = min(qstar2, qstar) .. max(qstar2, qstar), y = 0 .. infinity});
soln2:= fsolve({b1, b2}, {x = min(qstar2, qstar) .. max(qstar2, qstar), y = -infinity .. 0});
qcomplex1:= subs(soln1, x+I*y);
qcomplex2:= subs(soln2, x+I*y);
catch:
AreThereComplexRoots:= type(FAIL, 'truefalse');
end try;

# Compute the rest of the Roots
soln3:= fsolve({b1, b2}, {x = 0 .. infinity, y = 0 .. 10});
soln4:= fsolve({b1, b2}, {x = -infinity ..0, y = -infinity .. 0});
Imagroot1:=subs(soln3, I*y);
Imagroot2:= subs(soln4, I*y);
OddAsymptotes:= Vector[row]([seq(evalf((1/2)*(2*j+1)*Pi), j = 0 .. n)]);
AllAsymptotes:= sort(Vector[row]([OddAsymptotes, qstar]));

if AreThereComplexRoots
then gg:= [qcomplex1, qcomplex2,op(Roots(g, q = 0.1e-3 .. AllAsymptotes[1])),
seq(op(Roots(g, q = AllAsymptotes[i] .. AllAsymptotes[i+1])), i = 1 .. n)];
elif not AreThereComplexRoots
then gg:= [op(Roots(g, q = 0.1e-3 .. AllAsymptotes[1])), seq(op(Roots(g, q = AllAsymptotes[i] .. AllAsymptotes[i+1])), i = 1 .. n)];
end if:

# Remove the repeated roots if any & Redefine n

qq:= MakeUnique(gg):
m:= numelems(qq):

## Return all the plots
return qq, Imagroot1,Imagroot2, p, soln3, soln4;
end proc:

ans:=[doCalc(0.06)]:
ans[5];
{x = 0., y = 1.158748796 + 0. I}
ans[6];
{x = 0., y = -1.158748796}

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