# Inequalities

• Oct 7th 2010, 11:38 PM
Lukybear
Inequalities
How do we prove this expression?
x>0, y>0, z>0

x/y + y/z >= 2

I tried expanding, xz + y^2 >= 2yz

I see that if x = z, this expression is true, from x^2 + y^2 >= 2xy,
but how do we phrase that?
• Oct 8th 2010, 12:28 AM
BobP
$\frac{100}{101}+\frac{101}{102},$ (for example) is not greater than or equal to 2.