MHB Solve for integer solutions

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The equation $\sqrt{a-\sqrt{b}} + \sqrt{a+\sqrt{b}} = \sqrt{ab}$ is analyzed for integer solutions $(a, b)$. The discussion highlights the need to manipulate the equation to isolate terms and simplify the expressions. Various algebraic techniques are employed to explore potential integer pairs. The participants share insights and methods for solving the equation, leading to the identification of valid solutions. Ultimately, the focus remains on finding all integer pairs that satisfy the given equation.
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Determine all integer pairs of solutions for $(a,\,b)$ such that $\sqrt{a-\sqrt{b}}+ \sqrt{a+\sqrt{b}}=\sqrt{ab}$.
 
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anemone said:
Determine all integer pairs of solutions for $(a,\,b)$ such that $\sqrt{a-\sqrt{b}}+ \sqrt{a+\sqrt{b}}=\sqrt{ab}$.

square both sides to get$2a+2\sqrt{a^2-b} = ab$
or
$2\sqrt{a^2-b} = ab-2a$
square both sides to get
$4(a^2-b) = a^2b^2-4a^2b+4a^2$
or $a^2b^2= 4a^2b - 4b$
so $b=0$ or $b= 4- \frac{4}{a^2}$
b= 0 => a = 0
$b= 4- \frac{4}{a^2}$
gives a = 1 or 2
a = 1 gives b=0 this gives rise to contradiction
a= 2 gives b = 3 and this is the solution
so $(a,b) = (0,0)$ or $(2,3)$
it can be checked that $(a,b) = (2,3)$ is a solution by taking square root and adding. I have done the same
 
kaliprasad said:
square both sides to get$2a+2\sqrt{a^2-b} = ab$
or
$2\sqrt{a^2-b} = ab-2a$
square both sides to get
$4(a^2-b) = a^2b^2-4a^2b+4a^2$
or $a^2b^2= 4a^2b - 4b$
so $b=0$ or $b= 4- \frac{4}{a^2}$
b= 0 => a = 0
$b= 4- \frac{4}{a^2}$
gives a = 1 or 2
a = 1 gives b=0 this gives rise to contradiction
a= 2 gives b = 3 and this is the solution
so $(a,b) = (0,0)$ or $(2,3)$
it can be checked that $(a,b) = (2,3)$ is a solution by taking square root and adding. I have done the same

Thanks for participating, kaliprasad and for your solution!

My solution:
Squaring two times the given equality, we get $a^2((b-2)^2-4)+4b=0$, since $b≥0$, this implies $((b-2)^2-4)≤0$, solving it for $b$ we get $0≤b≤4$, and we get $(a,\,b)=(0,\,0)$ and $(2,\,3)$.
 
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