Table of Contents

## What is the linear equation for a circle?

The formula for the equation of a circle is (x – h)2+ (y – k)2 = r2, where (h, k) represents the coordinates of the center of the circle, and r represents the radius of the circle. If a circle is tangent to the x-axis at (3,0), this means it touches the x-axis at that point.

**What was the general formula of the equation of a circle?**

General form of Equation of a Circle The general equation of any type of circle is represented by: x2 + y2 + 2gx + 2fy + c = 0, for all values of g, f and c.

### How do you find F and G of a circle?

The General Form of the equation of a circle is x2 + y2 + 2gx +2fy + c = 0. The centre of the circle is (-g, -f) and the radius is √(g2 + f2 – c). Given a circle in the general form you can complete the square to change it into the standard form.

**How do you do circle theorems?**

Now for the theorems:

- The angle at the centre is twice the angle at the circumference.
- The angle in a semicircle is a right angle.
- Angles in the same segment are equal.
- Opposite angles in a cyclic quadrilateral sum to 180°
- The angle between the chord and the tangent is equal to the angle in the alternate segment.

## Why does the equation of a circle work?

The Circle Equation and Distance The mathematical definition for a circle is simply the set of points lying at a constant distance (the radius) from a fixed point (the center). In fact anything spinning around a point at a specific distance from that point will look circular. It’s just how geometry works!

**What is G in circle?**

General Equation of a Circle The general form of the equation of a circle is: x2 + y2 + 2gx + 2fy + c = 0. This general form is used to find the coordinates of the center of the circle and the radius, where g, f, c are constants.

### What are the 4 circle theorems?

First circle theorem – angles at the centre and at the circumference. Second circle theorem – angle in a semicircle. Third circle theorem – angles in the same segment. Fourth circle theorem – angles in a cyclic quadlateral.

**What are the 8 theorems of a circle?**

Circle Theorem 1 – Angle at the Centre.

## What is equation of a circle mean?

In fact the equation of a circle is not for finding area, but instead provides an algebraic way to describe a circle. The equation tells you where the center of the circle is in the xy-plane, and what its radius is. The equation of a circle of radius r centered at the point (h, k)

**What are the 6 main circle theorems?**

### What are the 2 equations of a circle?

x 2 + y 2 + 2 g x + 2 f y + c = 0 is used to work out the centre of the circle, and the radius. ( x − a ) 2 + ( y − b ) 2 = r 2 is used to write the equation of the circle when you know the centre and the radius.

**What is the use of equation of circle?**

In fact the equation of a circle is not for finding area, but instead provides an algebraic way to describe a circle. The equation tells you where the center of the circle is in the xy-plane, and what its radius is. Think of this equation as the master template for every possible equation of a circle.

## Why is the equation of a circle?

So set a = h and b = k in the formula, and because we know that the distance must be r, we can also replace d by r. Finally, if you square both sides of this equation, you end up with exactly the equation of a circle!

**Is the equation of a circle a function?**

A circle can be described by a relation (which is what we just did: x2+y2=1 is an equation which describes a relation which in turn describes a circle), but this relation is not a function, because the y value is not completely determined by the x value.

### Why is equation of a circle not a function?

**Is equation of a circle a function?**

## How to solve circle equation?

Identify the radius of a circle. The radius is the length from the center of a circle to the edge of the circle.

**How to determine circle equations?**

The x x and y y terms must be squared

### What is the standard equation for a circle?

The Center: (4,2)

**How do you solve a simple algebra equation?**

– √ (2x+9) – 5 = 0 First, move everything that isn’t under the radical sign to the other side of the equation: – √ (2x+9) = 5 – Then, square both sides to remove the radical: – (√ (2x+9)) 2 = 5 2 = – 2x + 9 = 25 Now, solve the equation as you normally would by combining the constants and isolating the variable: – 2x = 25 – 9 = – 2x = 16 – x = 8