1. Introduction to Parabolas SPI 3103.3.11 Graph conic sections (circles, parabolas, ellipses and hyperbolas) and understand the relationship between the standard form and the key characteristics of the graph.
2. Types of Conic Sections Parabola
3. Equation of a Parabola The general form for the equation of a parabola is y – k = a(x – h)2.
The equation may also be written in the form y = a(x – h)2 + k.
4. Important Information About Parabolas The vertex of a parabola is the ordered pair (h, k).
5. Important Information About Parabolas The axis of symmetry (axis) is the line x = h.
6. Important Information About Parabolas If a > 0, the parabola will open upward.
If a < 0, the parabola will open downward.
7. Important Information About Parabolas The larger a , the narrower the parabola will be.
8. Important Information About Parabolas To find the y-intercept of a parabola, substitute 0 for x; then solve the equation for y.
9. Practice With Parabolas
10. Practice with Parabolas For the following problems, give
a.) the vertex
b.) the axis of symmetry
c.) the direction the parabola
11. Practice with Parabolas y – 11 = 2(x + 7)2
y + 7 = –(x – 5)2
y = 5(x + 10)2
12. Practice with Parabolas 4. y – 7 = –8x2
5. y = 15x2
6. y = –x2