[tex]\it m_a-m_g \geq m_g-m_h\ \ \ \ (*)[/tex]
Cu substituția [tex]\it m_h=\dfrac{m_g^2}{m_a}[/tex], relația (*) devine:
[tex]\it m_a-m_g \geq m_g -\dfrac{m_g^2}{m_a} \Leftrightarrow m_a^2-m_a\cdot m_g \geq m_a\cdot m_g - m_g^2 \Leftrightarrow
\\\;\\ \\\;\\
\Leftrightarrow m_a^2-m_a\cdot m_g -m_a\cdot m_g +m_g^2 \geq0\Leftrightarrow m_a^2-2m_a\cdot m_g +m_g^2 \geq0\Leftrightarrow
\\\;\\ \\\;\\
\Leftrightarrow (m_a - m_g)^2\geq0\ \ \ (A)[/tex]
