inequality

rationalize the denominator .. then differentiate .. this is going to be easy ...

well do u see a denominator

how abt multiplying upar-niche with (x - √x2+b2)

f(x) = 2(a-x)(x-√x²+b²)/-b²

wat gud will this do [12] .. thinking ...........

Let y=2(a-x)(\sqrt{x^2+b^2}+x)=\dfrac{2b^2(a-x)}{\sqrt{x^2+b^2}-x}
Cross multiply to get y\sqrt{x^2+b^2}=2b^2(a-x)+xy
Now square both sides and treat the resulting expression as a quadratic in x. Since the roots has to be real, make the discriminant positive and you finally obtain
y^2\big((a^2+b^2)-y\big)\geq 0
from where you obtain
y\leq (a^2+b^2)