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## How do you find the equation of a circle given the center and a point?

Write the equation of a circle given the center and a point it passes

## How do you find the equation of a circle given two points?

Use the Distance Formula to find the equation of the circle. Substitute (x1,y1)=(h,k),(x2,y2)=(x,y) and d=r . Square each side. The equation of a circle with center (h,k) and radius r units is (x−h)2+(y−k)2=r2 .

## Why is the equation of a circle?

We know that the general equation for a circle is ( x – h )^2 + ( y – k )^2 = r^2, where ( h, k ) is the center and r is the radius. So add 21 to both sides to get the constant term to the righthand side of the equation. So, the center is at ( 0, 2 ) and the radius is 5.

## What is the equation for a semicircle?

In the case of a circle, the formula for area, A, is A = pi * r^2, where r is the circle’s radius. Since we know that a semicircle is half of a circle, we can simply divide that equation by two to calculate the area of a semicircle. So, the formula for the area of a semicircle is A = pi * r^2/2.

## What is general equation 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). Completing the square. Given a circle in the general form you can complete the square to change it into the standard form.

## What is the arc length formula?

Calculate the arc length according to the formula above: L = r * Θ = 15 * π/4 = 11.78 cm . Calculate the area of a sector: A = r² * Θ / 2 = 15² * π/4 / 2 = 88.36 cm² . You can also use the arc length calculator to find the central angle or the radius of the circle.

## What is the mean of pi?

Definition: Pi is a number – approximately 3.142. It is the circumference of any circle divided by its diameter. The number Pi, denoted by the Greek letter π – pronounced ‘pie’, is one of the most common constants in all of mathematics. It is the circumference of any circle, divided by its diameter.

## What is center of the circle?

The center of a circle is the point which is equidistant from all points on the circle. In the figure below, C is the center. The center point is often used to label the whole circle. The figure below would be called “the circle C”. For more on this see Circle definition.

## What is a formula of a circle?

The center-radius form of the circle equation is in the format (x – h)2 + (y – k)2 = r2, with the center being at the point (h, k) and the radius being “r”. This form of the equation is helpful, since you can easily find the center and the radius.

## Is a circle a function?

So the question is whether there’s a function whose graph is the circle. The answer is no, because each value in the domain is associated with exactly one point in the codomain, but a line passing through the circle generally intersects the circle at two points.

## What is slope intercept form?

The graph of the equation y = mx + b (where m and b are real numbers) is a line with slope, m, and y-intercept, b. This form of the equation of a line is called slope-intercept form. The slope of a line, m, is a measure of its steepness.