Solving a System of Equations: Circle and Line
This article will guide you through solving a system of equations involving a circle and a line. We will analyze the equations (x-3)^2 + (y+2)^2 = 16 and 2x + 2y = 10 to find their points of intersection.
Understanding the Equations
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(x-3)^2 + (y+2)^2 = 16 represents a circle with:
- Center: (3, -2)
- Radius: 4 (square root of 16)
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2x + 2y = 10 represents a line. To understand it better, we can rewrite it in slope-intercept form (y = mx + c):
- Slope (m): -1
- Y-intercept (c): 5
Solving the System
To find the points of intersection, we need to find the values of x and y that satisfy both equations simultaneously. We can achieve this through the following steps:
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Substitution Method:
- Solve the linear equation (2x + 2y = 10) for one variable (let's solve for x):
- x = 5 - y
- Substitute this expression for x into the circle equation:
- (5 - y - 3)^2 + (y + 2)^2 = 16
- Simplify and solve the resulting quadratic equation.
- Solve the linear equation (2x + 2y = 10) for one variable (let's solve for x):
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Solving the Quadratic Equation:
- Expanding the equation, we get:
- (2 - y)^2 + (y + 2)^2 = 16
- 4 - 4y + y^2 + y^2 + 4y + 4 = 16
- 2y^2 = 8
- y^2 = 4
- y = ±2
- Expanding the equation, we get:
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Finding the Corresponding x Values:
- Substitute the values of y back into the equation x = 5 - y:
- For y = 2, x = 5 - 2 = 3
- For y = -2, x = 5 - (-2) = 7
- Substitute the values of y back into the equation x = 5 - y:
Conclusion
Therefore, the points of intersection between the circle (x-3)^2 + (y+2)^2 = 16 and the line 2x + 2y = 10 are:
- (3, 2)
- (7, -2)
This means the line intersects the circle at two distinct points.