Graphs

Graphs

Area Problems

Example Continued

Step 3.Rewrite the equation using x and y variables and graph using a graphing calculator.

Area3

Step 4. Answer the questions.

  • What is the domain?
    • Since the inputs are based on width, the domain is all real numbers greater than or equal to 0; Area4a.
  • What is the range?
    • Since the outputs are based on area, the range is all real numbers greater than or equal to 0; Area5a.
  • For what values of l is the area zero?
    • This question is asking for the output to be zero, in other words the x-intercepts, which are (0, 0) and (0, 400).
  • For what value of l is there a maximum area?
    • This question is asking for the maximum value, in other words the vertex, which is (200, 80,000). The value of l that results in the maximum area is 200 feet.