Suppose ${3^x} + {4^x} = {5^x}$. What is zero of this equation? Suppose ${3^x} + {4^x} = {5^x}$.
What is zero of this equation?

$x=2$
Since
${\left( {\frac{3}{5}} \right)^x} + {\left( {\frac{4}{5}} \right)^x} = 1 = {(\sin x)^2} + {(\cos x)^2} \Rightarrow x = 2$
