Parabola Precalculus

The focus is at (2,0) and the vertex is at (-4,0).  What is the equation of the parabola?

• y² = 24(x+4)

• (y+4)² = -12x

• x² = 16(y+4)

• (x+4)²  = -20y

How do we define a parabola using its focus and directrix?

• A parabola is the set of all points that are the same distance from a single point, called the focus of the parabola, and a line, called the directrix of a parabola.

• A parabola is the set of all points that have a greater y value than a single point, called the focus of the parabola, and a lesser x value than a single point, called the directrix of the parabola.

• A parabola is a circle with a center point called the focus of the parabola, and a line from the center of the circle to the circle called the directrix of the parabola.

• A parabola is a square in which the center of the square is called the focus of the parabola, and the length of one side of the square is called the directrix of the parabola.

The focus is always inside the parabola.

• true

• false

All parabolas with a vertical directrix open the left or right.

• true

• false

Given a parabola with a vertex at (4,3) and a directrix of y=1, write the equation of the parabola.

Mathematical Equivalence

ON

Given a parabola with a vertex of (4,0) and a focus of (4,-1) write the equation of the parabola.

Mathematical Equivalence

ON

In a vertical parabola, which coordinate changes from the vertex to the focus?

Mathematical Equivalence

ON

In the equation of a parabola, d is the distance from the ​ (a)   to the ​ (b)   .

• vertex

• focus

• parabola

In a parabola, "p" tells you the distance from the ​ (a)   to the ​ (b)   and ​ (c)  

• vertex

• focus

• directrix

• origin

• parabola

• axis

In a horizontal parabola, which coordinate changes from the vertex to the focus?

Mathematical Equivalence

ON