# Question:How to make odetest return 0 on these solutions from dsolve

## Question:How to make odetest return 0 on these solutions from dsolve

I have few ode's which are solved by dsolve, but I am not able to get a zero from odetest(sol,ode). I tried the implicit option on the one which returns implicit solution, but I still do not get zero. I tried useInt as well.

Is there something else to do to verify the solution? My understanding is that if Maple returns a solution from dsolve, there there should be a way to get odetest() to verify the solution, but I could be wrong. Here are few examples, I have more if needed. This is Maple 18.01 on windows 7

restart;
MathematicalFunctions:-Version();
#       "C:\Program Files\Maple 18\lib\DEsAndMathematicalFunctions18.mla", `2014, July 25, 21:22 hours`
unassign(`print/ODESolStruc`):
ode1:=diff(y(x), x)+2*tan(y(x))*tan(x)-1:
ode2:=2*(diff(y(x), x))-3*y(x)^2-4*a*y(x)-b-c*exp(-2*a*x):
ode3:=(x^2+1)*(diff(y(x), x))+(y(x)^2+1)*(2*x*y(x)-1):
ode4:=x^7*(diff(y(x), x))+(2*(x^2+1))*y(x)^3+5*x^3*y(x)^2:
ode5:=(y(x)-x)*sqrt(x^2+1)*(diff(y(x), x))-a*sqrt((y(x)^2+1)^3):

sol1:=dsolve(ode1,y(x)):
sol2:=dsolve(ode2,y(x)):
sol3:=dsolve(ode3,y(x)):
sol4:=dsolve(ode4,y(x)):
sol5:=dsolve(ode5,y(x)):

odetest(sol1,ode1,implicit);  #not zero
odetest(sol2,ode2);             #not zero
odetest(sol3,ode3,implicit);  #not zero
odetest(sol4,ode4,implicit);  #not zero
odetest(sol5,ode5,implicit);  #not zero

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