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Practice

7.10.5 Practice

7.10.5 • Practice

Complete the following questions to practice the skills you have learned in this lesson.

  1. A quadratic function f is defined by f ( x ) = ( x − 7 ) ( x + 3 ) .
    1. Without graphing, identify the x -intercepts of the graph of f .
  1. ( 0 , − 7 ) , ( 0 , 3 )
  2. ( 0 , 7 ) , ( 0 , − 3 )
  3. ( − 7 , 0 ) , ( 3 , 0 )
  4. ( 7 , 0 ) , ( − 3 , 0 )
    1. Use the standard form of ( x − 7 ) ( x + 3 ) to identify the y -value of the y -intercept of the graph of f .
  1. Answer these questions for the equation y = x 2 − 5 x + 4 .
    1. What is the y -value of the y -intercept of this equation’s graph?
    1. An equivalent way to write this equation is y = ( x − 4 ) ( x − 1 ) . What are the x -intercepts of this equation’s graph?
  1. ( 0 , − 1 ) , ( 0 , − 4 )
  2. ( 0 , 1 ) , ( 0 , 4 )
  3. ( − 1 , 0 ) , ( − 4 , 0 )
  4. ( 1 , 0 ) , ( 4 , 0 )
  1. Noah said that if we graph y = ( x − 1 ) ( x + 6 ) , the x -intercepts will be at ( 1 , 0 ) and ( − 6 , 0 ) . Is Noah correct?
  1. Yes
  2. No
  1. Select two x -intercepts of this graph.

    A curve in an x y plane, origin O, with grid. Horizontal axis, scale negative 6 to 6, by 1’s. Vertical axis, scale negative 8 to 8, by 1’s. A curve passes through the points negative 1 comma 0, 1 comma negative 4, and 3 comma 0.
  1. 1
  2. − 1
  3. 3
  4. − 3
  1. Use the standard form of y = ( x − 2 ) ( x − 4 ) to identify the y -value of the y -intercept of the graph.