SOLUTION: identify the focus and directrix of the parabola given by {{{ y^2 = -4x }}}

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Question 756283: identify the focus and directrix of the parabola given by +y%5E2+=+-4x+
Answer by lwsshak3(11628) About Me  (Show Source):
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identify the focus and directrix of the parabola given by +y%5E2+=+-4x+
Given parabola opens leftward:
Its basic equation: y^2=-4px
vertex: (0,0)
axis of symmetry: y=0 or x-axis
4p=4
p=1
focus: (-1,0) (p-distance to left of vertex on the axis of symmetry)
directrix: x=1 (p-distance to right of vertex on the axis of symmetry)