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Circle Equation to Standard Form Calculator Linear Equation

Standard Form Equation:

\[ (x - h)^2 + (y - k)^2 = r^2 \]

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1. What is the Standard Form of a Circle Equation?

The standard form of a circle equation is \((x - h)^2 + (y - k)^2 = r^2\), where (h,k) is the center and r is the radius. This calculator converts from the linear-related form \(x^2 + y^2 + Dx + Ey + F = 0\) to standard form.

2. How Does the Calculator Work?

The calculator uses the following conversion:

\[ \text{Given: } x^2 + y^2 + Dx + Ey + F = 0 \] \[ \text{Center: } (h,k) = \left(-\frac{D}{2}, -\frac{E}{2}\right) \] \[ \text{Radius: } r = \sqrt{h^2 + k^2 - F} \]

Where:

Explanation: The calculator completes the square algebraically to transform the equation into standard form.

3. Importance of Standard Form

Details: The standard form immediately reveals the circle's center and radius, making it essential for graphing and geometric analysis.

4. Using the Calculator

Tips: Enter the coefficients of x and y, and the constant term from your equation. The calculator will handle both proper circles (positive radius) and degenerate cases.

5. Frequently Asked Questions (FAQ)

Q1: What if I get an imaginary radius?
A: This means the equation doesn't represent a real circle (the radius squared is negative).

Q2: Can I use this for equations without x² and y² terms?
A: The equation must have x² and y² terms with coefficient 1 to use this method directly.

Q3: What does a radius of zero mean?
A: This represents a single point (a degenerate circle) at the center coordinates.

Q4: How do I handle equations with different coefficients for x² and y²?
A: You must first divide the entire equation by the common coefficient to make them both 1.

Q5: Why is standard form useful?
A: It makes the circle's geometric properties immediately visible and simplifies graphing and analysis.

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