4.5 Writing a Function Rule I can write equations that represent functions.

Writing

Writing and Evaluating  Below is a concert seating plan. If reserved seating is sold out, TOTAL revenue depends on the number of general tickets sold. Write a function rule and find the maximum possible total revenue.

Continued  There are 10 rows of 12 seats for $25 each that have already been sold.  That is, they have already made $(25 ∙ 10 ∙ 12)  General seating costs $10 each.  Pattern?  Rule?  So, R = 10n  Maximum revenue occurs when all general seating is sold. (30 rows of 16 seats)  R = 10(30 ∙ 16) = 10(480) =  Maximum total revenue is $7800

Writing a Nonlinear Function Rule  Write a function rule for the area of a rectangle whose length is 5 ft more than its width. What is the area of the rectangle when its width is 9 ft?  First represent the general relationship  Now, revise the model to represent the length of 5 ft more than the width  Write the function rule.  A = (w + 5) ∙ w or A = w 2 + 5w  When the width is 9 ft…  A = (9) = = 126 ft 2

Assignment  ODDS ONLY  P.265 #9-27