Undefined function or variable 'dslove'.

syms g m M T G x y V(t)
fun = @(x,y)((2*pi*g*(1-(V(t))^2)^2)/m^2)*y.*(((x-(m*V/sqrt(1-(V(t))^2))).^2/(1-(V(t))^2))+y.^2).*exp(-(sqrt(m^2+x.^2+y.^2)-M)/T);
Q1= int(fun,x,-inf,G*m*V(t));
Q2= int(int(fun,x,-inf,G*m*V(t)),y,0,inf);
Q3= int(fun,x,G*m*V(t),inf);
Q4= int(int(fun,x,G*m*V(t),inf),y,0,inf);
eqn=diff(V,t)==Q2-Q4;
dslove(eqn)

[madhan ravi]

dsolve()
%^^^---- !