Let a, b, c be real numbers such that a+b+c=a b c. Prove that \frac{1}{a^{2}+1}+\frac{1}{b^{2}+1}+\frac{1}{c^{2}+1} \geq \frac{3}{4}.
Let a, b, c be real numbers such that a+b+c=a b c. Prove that \frac{1}{a^{2}+1}+\frac{1}{b^{2}+1}+\frac{1}{c^{2}+1} \geq \frac{3}{4}.