MathDB

5

Part of 2013 Philippine MO

Problems(1)

PMO Finals #5

Source:

2/3/2013
Let rr and ss be positive real numbers such that (r+s−rs)(r+s+rs)=rs(r+s-rs)(r+s+rs)=rs. Find the minimum value of r+s−rsr+s-rs and r+s+rsr+s+rs
inequalities