#### How to find the equation of a circle

## What is the formula for a circle on a graph?

The equation of a circle appears as (x – h)^{2} + (y – v)^{2} = r^{2}. This is called the center-radius form (or standard form) because it gives you both pieces of information at the same time.

## How do you write the equation of a circle?

First you need to know that the equation for a circle is (x-a)^2 + (y-b)^2 = r^2 where the center is at point (a,b) and the radius is r. so for instance (x-2)^2 + (y-3)^2 = 4 would have the center at (2,3) and have a radius of 2 since 4 = 2^2.

## How do I calculate the area of a circle?

The area of a circle is pi times the radius squared (A = π r²).

## How do you find the equation of a line?

The equation of a line is typically written as y=mx+b where m is the slope and b is the y-intercept.

## What’s a standard form?

Standard form is a way of writing down very large or very small numbers easily. So 4000 can be written as 4 × 10³ . This idea can be used to write even larger numbers down easily in standard form. Small numbers can also be written in standard form.

## How do you graph a circle on a calculator?

Solution Using DRAW:Press ZOOM#4 (ZDecimal) to go to a graphing screen.To graph the circle, press 2nd PRGM (DRAW) #9 Circle.Move the cursor to the “h” value of +2 by using the arrows.Move the cursor to the “k” value of +1 by using the arrows.Press ENTER to set the point for the center of the circle.

## Is a circle on a graph a function?

A circle is a set of points in the plane. A function is a mapping from one set to another, so they’re completely different kinds of things, and a circle cannot be a function. The graph of a function, , is the set of pairs, for all in the domain, which can be interpreted as points in a plane.