Quetion to find the equation of a parabola i want check

  • Thread starter r-soy
  • Start date
  • Tags
    Parabola
In summary, the equation of a parabola can be found using the definition of a parabola and the distance formula. For part a), the directrix is x = -4 and the focus is (2,2). For part b), the directrix is x = 2 and the focus is (6,-4). However, the provided work for part a) is not consistent with the given requirements, as the equation given has y = -4 instead of x = -4. For part b), the parabola should open to the left or right since the directrix is x = 2, but the provided graph shows it opening upwards. Additionally, the directrix is not shown in the provided graph and the vertex
  • #1
r-soy
172
1
Hi all

Use the definition of a parabola and the distance formula to find the equation of a parabola with

a ) directix x = -4 and focus (2,2 )
B ) directix x = 2 and focus (6,-4 )

my answer :

383986876.jpg


206452772.jpg
 
Physics news on Phys.org
  • #2
r-soy said:
Hi all

Use the definition of a parabola and the distance formula to find the equation of a parabola with

a ) directix x = -4 and focus (2,2 )
B ) directix x = 2 and focus (6,-4 )
Your work for a) is not consistent with the requirements above. In your work for a, you have y = -4. Which is it?

For b), because the directrix is x = 2, the parabola has to open to the left or right. Yours opens upward, which is wrong.

Also, you don't draw the directrix for either parabola in your graph. The vertex of the parabola is halfway between the directrix and focus, so you can use the directrix and focus to figure out where the vertex is.

r-soy said:
my answer :

383986876.jpg


206452772.jpg
 

1. What is the general form of a parabola equation?

The general form of a parabola equation is y = ax^2 + bx + c, where a, b, and c are constants and x is the independent variable. This form is also known as the standard form.

2. How do I identify the vertex of a parabola given its equation?

The vertex of a parabola can be identified by finding the values of x and y that make the equation equal to zero. These values, denoted as (h, k), represent the coordinates of the vertex.

3. What is the role of the coefficient "a" in a parabola equation?

The coefficient "a" in a parabola equation determines the shape and direction of the parabola. If a is positive, the parabola opens upwards, and if a is negative, the parabola opens downwards. The absolute value of a also determines the steepness of the curve.

4. Can a parabola have more than one x-intercept?

Yes, a parabola can have zero, one, or two x-intercepts, depending on the values of its coefficients. If the discriminant (b^2 - 4ac) is greater than zero, the parabola will have two x-intercepts. If the discriminant is equal to zero, the parabola will have one x-intercept. And if the discriminant is less than zero, the parabola will have no x-intercepts.

5. How can I use the equation of a parabola to graph it?

To graph a parabola using its equation, you can use the coordinates of the vertex as the center point and then plot additional points by substituting different values of x into the equation. You can also use the axis of symmetry, which is a vertical line passing through the vertex, to find other points on the parabola.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
10
Views
3K
  • Precalculus Mathematics Homework Help
Replies
2
Views
1K
  • Precalculus Mathematics Homework Help
Replies
2
Views
1K
  • Precalculus Mathematics Homework Help
Replies
4
Views
1K
  • Precalculus Mathematics Homework Help
Replies
4
Views
1K
  • Precalculus Mathematics Homework Help
Replies
3
Views
2K
  • Calculus and Beyond Homework Help
Replies
21
Views
1K
  • Precalculus Mathematics Homework Help
Replies
17
Views
7K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Precalculus Mathematics Homework Help
Replies
4
Views
1K
Back
Top