Here are several functions that work with a vector. For each function,

$1$: Briefly describe what the function returns $($e$.$g$.$ "the largest value in the vector"$),$ and

$2$: Give the function a pithy $($brief and descriptive$)$ name $($e$.$g$.$max$).$

a$)$ bool $f1($const vectorxv$(x2==1)f2i=0v[i]2==1if3j=-1i=0v[i]2==1j=$ijf$4xv(x2==1)f5y=0xv(x2==1)y=x{y}_{i}ii$