What is the rule for the following function

Question

x 0 1 2 4.5

Y 0 .5 2 3

Answer 1

x =a(y-k)^2+ h

0 = ak^2 +h

.5 = a -2ak +ak^2 +h

2 =4a -4ak + ak^2 +h

a-2ak =.5

3a-2ak =1.5

2a =1

a=.5

k=0

h==0

x=f(y)= .5y^2

or

y=f(x)=+/-sqr2x

3= sqr(2(4.5)=sqr9

4.5= .5(3^2)= 9/2 = 4.5