Big Ideas Math Algebra 2, 2014
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Big Ideas Math Algebra 2, 2014 View details
2. Properties of Rational Exponents and Radicals
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Exercise 82 Page 250

Which variable is raised to the second power? Does it mean that the axis of symmetry of the parabola is a horizontal or a vertical line?

Vertex: (0, 0)
Focus: ( 0, 1/8 )
Directrix: y=- 1/8
Axis of Symmetry: x=0
Graph:

Practice makes perfect

Before we begin, note that in the given equation the variable that is raised to the second power is x. y=2x^2 Therefore, the axis of symmetry of the parabola is a vertical line.

Finding the Desired Information

In order to match this form perfectly, let's rewrite our equation so that the parenthetical factor has a coefficient. y=2x^2 ⇔ y=2(x-0)^2+0 We need to identify the values of h, k, and p. Let's start with p. To do so, we will solve the equation 14 p=2. We set it equal to 2, because 2 is the coefficient of the parenthetical factor.
1/4p=2
â–Ľ
Solve for p
1=8p
1/8=p
p=1/8
Knowing that p= 18, we can rewrite the equation. y=2x^2 ⇕ y=1/4( 18 ) (x- 0)^2+ 0 Now we have that h= 0, k= 0, and p= 18. By recalling the corresponding formulas we can find the vertex, focus, directrix, and axis of symmetry of the parabola.
Vertex Focus Directrix Axis of Symmetry
Formula ( h, k) ( h, k+ p) y= k- p x= h
Value ( 0, 0) ( 0, 0+ 1/8)
⇓
( 0, 1/8 )
y= 0- 1/8
⇓
y=- 1/8
x= 0

Drawing the Parabola

Now, let's draw the parabola using the obtained information.