i want to find roots of a polynomial whose power is 2.59 and 4.06?

aa=abs(A^2)*Vr^4+2*abs(A)*(Vr^2)*abs(Z)*(P0*Vr^np*cos(thetaz-deltaA)+Q0*Vr^nq*sin(thetaz-deltaA))-Vs^2*Vr^2+(P0^2*Vr^2*np+Q0^2*Vr^2*nq)*abs(Z^2);

where

np=2.59

nq=4.06

i tried using

syms Vr;

aa=abs(A^2)*Vr^4+2*abs(A)*(Vr^2)*abs(Z)*(P0*Vr^np*cos(thetaz-deltaA)+Q0*Vr^nq*sin(thetaz-deltaA))-Vs^2*Vr^2+(P0^2*Vr^2*np+Q0^2*Vr^2*nq)*abs(Z^2);

ans1=vpasolve(aa,Vr);

please suggest with example

[Walter Roberson]

By definition, polynomials only have non-negative integer powers of the variable they are polynomial in.