If the numbers are a and b: ab=2, a+b=4. b=4-a so a(4-a)=2; 4a-a^2-2=0; a^2-4a+2=0;
this can be written: a^2-4a+4-2=0 or (a-2)^2=2; a-2=+sqrt(2) and a=2+sqrt(2). The two solutions are in fact a and b. So a=2+sqrt(2)=3.1414 and b=2-sqrt(2)=0.5858 (approx).