The problem asks us to graph the quadratic equation $y = x^2 + 2x - 8$ on a given graph and to discuss the properties of the resulting parabola.
2025/6/4
1. Problem Description
The problem asks us to graph the quadratic equation on a given graph and to discuss the properties of the resulting parabola.
2. Solution Steps
First, we need to find some key points on the parabola to plot. We can find the vertex, the y-intercept, and the x-intercepts.
The x-coordinate of the vertex is given by , where and .
To find the y-coordinate of the vertex, we substitute into the equation:
So the vertex is .
To find the y-intercept, we set :
So the y-intercept is .
To find the x-intercepts, we set :
We can factor the quadratic equation:
So the x-intercepts are and . The points are and .
Now we have the vertex , the y-intercept , and the x-intercepts and .
We can plot these points and draw the parabola.
Observations about quadratics and parabolas:
- They are U-shaped.
- They have a vertex, which is either a minimum or a maximum point.
- They are symmetrical about the vertical line that passes through the vertex.
- They can have 0, 1, or 2 x-intercepts.
How are they similar?
- Quadratics and parabolas are essentially the same thing. The graph of a quadratic equation is a parabola.
How are they different from other things you've graphed?
- Unlike linear equations (straight lines), parabolas are curved.
- Unlike some other curves, parabolas have a well-defined vertex and symmetry.
3. Final Answer
The graph of is a parabola with vertex , y-intercept , and x-intercepts and . Quadratics and parabolas are the same. Parabolas are different from lines because they are curved. They have a vertex and an axis of symmetry.