var a,xk,dx,xn,y,x:real;
begin
read(xn,xk,dx);
read(a);
 x:=xn ;
while x<=xk do begin
y:=power(x*x-ln(sqrt(a*x)/ln(10)),1/3)/(a*x);
writeln('x=',x,'  y=',y:2:3);
x:=x+dx;
end;


end.