What is the focus of the following graph?
parabola opening to the left, with vertex at (0, 0) and directrix at x equals 2

(-3, 0)

(3, 0)

(2, 0)

(-2, 0)http://curriculum.kcdistancelearning.com/courses/ALG2x-HS-A09/b/assessments/C-ParabolasQuiz/A2_8.2_Quiz_2q.gif

Question

What is the focus of the following graph?
parabola opening to the left, with vertex at (0, 0) and directrix at x equals 2
 	
	
(-3, 0)
	
(3, 0)
	
(2, 0)
	
(-2, 0)http://curriculum.kcdistancelearning.com/courses/ALG2x-HS-A09/b/assessments/C-ParabolasQuiz/A2_8.2_Quiz_2q.gif

anonymous · Answer

It's (-2,0) because the directrix and the focus point are always the same length away from the origin which is (0,0). Therefore if the line of directrix is x=2 then the focus is the other way but same distance at the point (-2,0)

anonymous · Answer

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