Question 1158431
The following are functions of x, because to every x in the domain there i just one value assigned in to the other variable:
b. f(x)=sqrt(x^2+3)
c.h(x)=1/x^2
d.x=3
f.{(2,3),(3,4),(4,4),(5,6)}
 
The relation a. between children and stuffed animals is probably understood as not a function, because if I ask what stuffed animal belongs to Susie, , there may be more than one.
The relation e.x^2+y^2=5 graphs as a circle of radius {{{sqrt(5)}}} , centered at the origin, but it is not a function, because for every value of x, except {{{x=sqrt(5)}}} and {{{x=-sqrt(5)}}} there are two values of y.