Lesson 4.1 Function Operations

Let

and

Find

Let

and

Find

Let

and

Find

Let

and

Find

Sri turns on the bathtub spout to warm up the water already in the tub. The amount of water (in gallons) in the tub x minutes after turning on the spout if no other water leaves or enters is modeled by f(x) = 2.4x + 15. When Sri turns on the spout, however, he accidentally opens the drain, which drains 3.1 gallons per minute from the tub. Use a function operation to write a model for the amount of water in the tub x minutes after the spout is turned on and the drain is opened.

If Sri leaves when he turns on the water and returns 10 minutes later, how much water is in the tub?

The function model p(x) = 5 + 2x represents the number of employees p of a small company where x is the number of years after 2018. The average employee salary s in thousands of dollars for this period can be modeled by s(x) = 1.05 x + 46. Use a function operation to write a model for the total salary T for the staff at the company after x years.

If these models hold until 2030, what is the approximate total staff salary in 2030?

Let

Given that

what is g(x)?