To determine the cost of the mail, we simply substitute the mass of the package to the given function. Mathematical functions are used to relate two variables, observing how changing one variable affects the other variable. For this case, the cost of a mail and the weight of the package are related by the function y = 0.7x2 –2.5x + 3 where x represents the mass in units of pounds (lb) and y is the cost in units of dollars ($). We calculate cost as follows:
y = 0.7x^2 –2.5x + 3
y = 0.7(5)^2 –2.5(5)+ 3
y = 8 dollars
Therefore, the cost of mailing a 5 lb package would be 8 dollars.
