Staar Parabolas Review

Look at the graph of the parabola shown. Select the choice that states a possible focus and directrix for the graph.

• Focus (-4, 4)

  Directrix x=8

• Focus (-4, 4)

  Directrix y=8

• Focus (4, -4)

  Directrix x=8

• Focus (4, -4)

  Directrix y=8

• (-4, -8)

• (4, -8)

• (-8, 4)

• (-8, -4)

• (0, 2)

• (0, -2)

• (-4, -2)

• (-4, 2)

• x=-6

• y=-6

• x=6

• y=6

Select the equation that represents a parabola in vertex form with vertex (3, -2) and directrix x=-6

Select the equation that represents the parabola graphed on the coordinate plane.

The cross section of a satellite dish is a parabola. Suppose a satellite dish receiver is located at the focus of the cross section, 10 feet in front of the vertex.

Assume the vertex is at the origin and that the parabola is concave left. Write an equation that represents the cross section of a satellite dish.

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Formula for vertical parabolas (open up or down):

Formula for horizontal parabolas (open left or right):