Finding Points Using Technology

Oct 13, 2025 by talynt.org 8 views

Introduction

In this article, we will explore how to use technology to find points and graph a quadratic function. We will be working with the function $y=-(x+2)^2+4$ . This function is a quadratic function in the form of $y=ax^2+bx+c$ , where $a=-1$ , $b=-4$ , and $c=4$ . We will use technology to find at least five points that fit on the axes below and then graph the function.

Finding Points Using Technology

To find points that fit on the axes below, we can use a graphing calculator or a computer algebra system (CAS). These tools allow us to input the function and find points that satisfy the equation.

Using a Graphing Calculator

To find points using a graphing calculator, follow these steps:

Enter the function: Enter the function $y=-(x+2)^2+4$ into the calculator.
Graph the function: Graph the function to see the shape of the curve.
Find points: Use the calculator to find points that fit on the axes below. You can do this by using the "intersect" or "solve" feature to find the points where the curve intersects the x-axis and y-axis.

Using a Computer Algebra System (CAS)

To find points using a CAS, follow these steps:

Enter the function: Enter the function $y=-(x+2)^2+4$ into the CAS.
Graph the function: Graph the function to see the shape of the curve.
Find points: Use the CAS to find points that fit on the axes below. You can do this by using the "solve" or "intersect" feature to find the points where the curve intersects the x-axis and y-axis.

Plotting Points

Once we have found the points that fit on the axes below, we can plot them on a graph. To plot a point, we need to know the x-coordinate and the y-coordinate of the point.

Plotting Points Using a Graphing Calculator

To plot points using a graphing calculator, follow these steps:

Enter the point: Enter the x-coordinate and y-coordinate of the point into the calculator.
Plot the point: Use the calculator to plot the point on the graph.

Plotting Points Using a Computer Algebra System (CAS)

To plot points using a CAS, follow these steps:

Enter the point: Enter the x-coordinate and y-coordinate of the point into the CAS.
Plot the point: Use the CAS to plot the point on the graph.

Graphing the Function

Once we have plotted at least five points that fit on the axes below, we can graph the function. To graph the function, we need to connect the points with a smooth curve.

Graphing the Function Using a Graphing Calculator

To graph the function using a graphing calculator, follow these steps:

Graph the function: Use the calculator to graph the function.
Adjust the graph: Adjust the graph to make sure it is smooth and continuous.

Graphing the Function Using a Computer Algebra System (CAS)

To graph the function using a CAS, follow these steps:

Graph the function: Use the CAS to graph the function.
Adjust the graph: Adjust the graph to make sure it is smooth and continuous.

Conclusion

In this article, we have explored how to use technology to find points and graph a quadratic function. We have used a graphing calculator and a computer algebra system (CAS) to find points that fit on the axes below and then graph the function. We have also discussed how to plot points and graph the function using these tools.

Example Points

Here are five example points that fit on the axes below:

x	y
-2	8
-1	5
0	4
1	3
2	2

Graph

Here is the graph of the function $y=-(x+2)^2+4$ :

Graph

Q: What is a quadratic function?

A: A quadratic function is a polynomial function of degree two, which means the highest power of the variable (usually x) is two. The general form of a quadratic function is $y=ax^2+bx+c$ , where $a$ , $b$ , and $c$ are constants.

Q: What is the vertex of a quadratic function?

A: The vertex of a quadratic function is the point on the graph where the function changes direction. It is the lowest or highest point on the graph, depending on whether the parabola opens upward or downward.

Q: How do I find the vertex of a quadratic function?

A: To find the vertex of a quadratic function, you can use the formula $x=-\frac{b}{2a}$ . This will give you the x-coordinate of the vertex. To find the y-coordinate, plug the x-coordinate back into the function.

Q: What is the axis of symmetry of a quadratic function?

A: The axis of symmetry of a quadratic function is a vertical line that passes through the vertex of the parabola. It is the line of symmetry for the graph.

Q: How do I graph a quadratic function?

A: To graph a quadratic function, you can use a graphing calculator or a computer algebra system (CAS). You can also use the following steps:

Find the vertex: Find the vertex of the parabola using the formula $x=-\frac{b}{2a}$ .
Find the x-intercepts: Find the x-intercepts of the parabola by setting $y=0$ and solving for $x$ .
Find the y-intercept: Find the y-intercept of the parabola by setting $x=0$ and solving for $y$ .
Plot the points: Plot the points on the graph, including the vertex, x-intercepts, and y-intercept.
Draw the graph: Draw the graph of the parabola, using the points you plotted.

Q: What is the difference between a quadratic function and a linear function?

A: A quadratic function is a polynomial function of degree two, while a linear function is a polynomial function of degree one. A quadratic function has a parabolic shape, while a linear function has a straight line shape.

Q: Can I graph a quadratic function by hand?

A: Yes, you can graph a quadratic function by hand, but it can be time-consuming and may not be as accurate as using a graphing calculator or a computer algebra system (CAS).

Q: What are some common mistakes to avoid when graphing a quadratic function?

A: Some common mistakes to avoid when graphing a quadratic function include:

Not finding the vertex: Failing to find the vertex of the parabola can make it difficult to graph the function accurately.
Not finding the x-intercepts: Failing to find the x-intercepts of the parabola can make it difficult to graph the function accurately.
Not finding the y-intercept: Failing to find the y-intercept of the parabola can make it difficult to graph the function accurately.
Not plotting the points: Failing to plot the points on the graph can make it difficult to graph the function accurately.

Q: How do I check my work when graphing a quadratic function?

A: To check your work when graphing a quadratic function, you can use the following steps:

Check the vertex: Check that the vertex of the parabola is correct.
Check the x-intercepts: Check that the x-intercepts of the parabola are correct.
Check the y-intercept: Check that the y-intercept of the parabola is correct.
Check the graph: Check that the graph of the parabola is correct.

By following these steps and avoiding common mistakes, you can graph a quadratic function accurately and efficiently.