IM Alg1.4.5 Lesson: Using Function Notation to Describe Rules (Part 2)
Consider the equation . What value of would make the equation true when is 7? Explain your reasoning.
What value of would make the equation true when is 100? Explain your reasoning.
What value of would make the equation true when is 12? Explain your reasoning.
What value of would make the equation true when is 60? Explain your reasoning.
A college student is choosing between two data plans for her new cell phone. Both plans include an allowance of 2 gigabytes of data per month. The monthly cost of each option can be seen as a function and represented with an equation:
In each function, the input, , represents the gigabytes of data used over the monthly allowance.
The student decides to find the values of and and compare them. What are those values?
After looking at some of her past phone bills, she decided to compare and . What are those values?
Describe each data plan in words.
Graph each function on the same coordinate plane.
Explain which plan you think she should choose.
The student only budgeted $50 a month for her cell phone. She thought, “I wonder how many gigabytes of data I would have for $50 if I go with Option B?” and wrote . What is the answer to her question? Explain how you know.
Describe a different data plan that, for any amount of data used, would cost no more than one of the given plans and no less than the other given plan. Explain how you know this data plan would meet these requirements.
The function is defined by the equation .
Use the applet below to find the value of each expression:
Use graphing technology to solve each equation: