We could also represent this function with an equation, A = #r2. We say that the input of
the function, r, is the independent variable and the output of the function, A, is the
dependent variable. We can choose any value for r, and then the value of A depends on
the value of r. We could also represent this function with a table or as a graph. Depending
on the question we investigate, different representations have different advantages. You
may recognize this rule and know that the area of a circle depends on its radius.
Here is a task to try with your student:
Jada can buy peanuts for $0.20 per ounce and raisins for $0.25 per ounce. She has $12 to
spend on peanuts and raisins to make trail mix for her hiking group.
1. How much would 10 ounces of peanuts and 16 ounces of raisins cost? How much
money would Jada have left? 6
2. Using p for pounds of peanuts and r for pounds of raisins, an equation relating how
much of each they buy for a total of $12 is 0.2p+ 0.25r = 12. If Jada wants 20 ounces
of raisins, how many ounces of peanuts cán she afford? 7