Two traveling sinusoidal waves are described by the wave functions

y$1=5\mathrm{.}50$ sin $[(4\mathrm{.}25$x $1125$t$)]$y$2=5\mathrm{.}50$ sin $[(4\mathrm{.}25$x $1125$t $0\mathrm{.}250)]$

where x$,$ y$1,$ and y$2$ are in meters and t is in seconds.

$($a$)$ What is the amplitude of the resultant wave function

y$1+$ y$2?$

m

$($b$)$ What is the frequency of the resultant wave function?