 # Find the point(s) of intersection algebraically..

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Find the point(s) of intersection algebraically.

Question of the Day EOC REVIEW

Review HW

WRITING EQUATIONS Parabolas

When x is squared If p is POSITIVE the parabola opens UP If p is NEGATIVE the parabola opens DOWN

When y is squared If p is POSITIVE the parabola opens RIGHT If p is NEGATIVE the parabola opens LEFT

Writing the equation of the parabola Graph everything you have been given. Find the p-value by counting the distance:  Between the Vertex and Focus (this is the p- value) or  Between the Vertex and Directrix (this is the p-value) or  Between the Directrix and Focus (take half to get the p-value) Decide if the graph opens up, down, left, or right. Figure out if this makes p negative or positive. Decide if x is squared or the y is squared. Find the vertex (h, k). Plug in your values and simplify the equation.

1. Focus (0, 1) Directrix: y = 5 F V (0, 3) Graph Opens DOWN (x 2 ) p = -2 So multiply it by 4. Graph what you have. Find the p- value. Find (h, k). Which variable is squared?

2. Focus (2, 0) Directrix: x = -1 F V (.5, 0) Graph Opens RIGHT (y 2 ) p = 1.5 So multiply it by 4. Graph what you have. Find the p- value. Find (h, k). Which variable is squared?

3. Graph what you have. Find the p- value. Find (h, k). Which variable is squared? Focus (0, -5) Directrix: y = 0 F V (0, -2.5) Graph Opens DOWN (x 2 ) p = -2.5 So multiply it by 4.

4. Graph what you have. Find the p- value. Find (h, k). Which variable is squared? Focus (-4, 0) Directrix: x = -2 F V (-3, 0) Graph Opens LEFT (y 2 ) p = -1 So multiply it by 4.

5. Graph what you have. Find the p- value. Find (h, k). Which variable is squared? Vertex (0, 0) Focus (0, -2) F V Graph Opens DOWN (x 2 ) p = -2 So multiply it by 4.

6. Graph what you have. Find the p- value. Find (h, k). Which variable is squared? Vertex (0, 0) Focus (0, -3) F V Graph Opens DOWN (x 2 ) p = -3 So multiply it by 4.

7. Graph what you have. Find the p- value. Find (h, k). Which variable is squared? Focus (0, 4) Directrix: x = -4 V (-2, 4) F Graph Opens RIGHT (y 2 ) p = 2 So multiply it by 4.

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