If the area included between the two parabolas  $y^2=4a(x+a)$ and $y^2=4b(b-x)$  is $\frac{16}{3}$ , then  $(a,b>0)$

$a+b=ab$

AM and GM of a and b are reciprocals of each other $\forall a,b>0$

AM and GM of a and b are equal  $\forall a,b>0$

$\sqrt{\frac{a^2+b^2}{2}}=a+b$