Given $\forall x,y>0$
Prove that $x^y+y^x\ge1$
I have tried weighted inequalities and Jensen's but unfortunately ended up no where.
Please help me. (I know this is a basic inequality).
Given $\forall x,y>0$
Prove that $x^y+y^x\ge1$
I have tried weighted inequalities and Jensen's but unfortunately ended up no where.
Please help me. (I know this is a basic inequality).
Case I: $x$ and $y$ both greater than 1
$x^y, y^x > 1$
Hence, proved
Case II: x is 1 (without loss of generality)
$x^y$ = 1
$1 + y^x > 1$
Hence, proved
Case III: $x$ and $y$ both less than 1.
I can explain why this could be true informally. For both x and y less than 1, the power is actually a root, and a root of a number less than 1 will increase its value. Still, can't show that it will be at least one.