Chapter 4 - An Introduction to Functions - 4-3 Patterns and Nonlinear Functions - Practice and Problem-Solving Exercises - Page 250: 16

y= 0.5$x^{2}$

For the each y-coordinate{0, 0.5 , 2 , 4.5 , 8} , we could find they could all divide by 0.5 and later we could find this property of each ordered pairs . (0,0) 0=0.5x$0^{2}$ (1,0.5) 0.5=0.5x$1^{2}$ (2,2) 2= 0.5x$2^{2}$ ........ As a result , we could determine that the rule is y= 0.5$x^{2}$