Graphing the Equation (x-2)^2 + (y+1)^2 = 9
The equation (x-2)^2 + (y+1)^2 = 9 represents a circle in the Cartesian coordinate system. Let's break down how to graph it:
Understanding the Equation
This equation is in the standard form of the circle equation:
(x - h)^2 + (y - k)^2 = r^2
Where:
- (h, k) represents the center of the circle
- r represents the radius of the circle
Identifying the Center and Radius
By comparing our equation (x-2)^2 + (y+1)^2 = 9 to the standard form, we can identify:
- Center (h, k): (2, -1)
- Radius r: √9 = 3
Graphing the Circle
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Plot the center: Mark the point (2, -1) on your coordinate plane.
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Draw the circle: Using the center as the starting point, measure out a distance of 3 units (the radius) in all directions (up, down, left, right). Mark these points.
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Connect the points: Connect the marked points to form a smooth circle.
Key Features of the Graph
- Center: The center of the circle is at point (2, -1).
- Radius: The radius of the circle is 3 units.
- Symmetry: The circle is symmetrical around both the x-axis and y-axis.
- Shape: It's a perfect circle, with all points equidistant from the center.
Visualizing the Equation
The equation (x-2)^2 + (y+1)^2 = 9 describes all the points (x, y) that are exactly 3 units away from the point (2, -1). This is why the graph is a circle.