Question 40
Characterise all non-negative real numbers $a$ and $b$ such that the equation
$$
\sqrt{x + 2\sqrt{a}} - \sqrt{x - 2\sqrt{a}} = 2b
$$
has at least one real solution. (All roots are assumed to be real.)
$$
\sqrt{x + 2\sqrt{a}} - \sqrt{x - 2\sqrt{a}} = 2b
$$
has at least one real solution. (All roots are assumed to be real.)