Graphs of Quadratic Equations

1. Consider the quadratic function f(x)  –2x2 + = 5x + 2. Find the y-intercept and the equation of the axis of symmetry.

Write the following quadratic function in the vertex form. Then, identify the axis of symmetry.

2. y = x2 + 4x – 6 = 0

3. y = -3x2 – 18x

Find the coordinates of the vertex of the quadratic function.

4. y = -52 + 20x – 13

5. Write an equation for the parabola whose vertex is at (2,6) and which passes through (4, -4).

6. Graph the quadratic equation or inequality. y = (x – 2)2 – 5

Answers (highlight below)

1. The y-intercept is + 2. The equation of axis of symmetry is x = (5/4) 

2. The vertex form of the function is y = (x+2)2 – 10. The equation of the axis of symmetry is x = -2. 

3.  The vertex form of the function is y = -3(x – 3) + 27. The equation of the axis of symmetry is x = 3. 

4. (2,7))

5.  y = -2.5(x – 2)2 + 6

6. Goes through points (-1, 4) (0, 1) (4, -1) (5, 4)

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