Circles in the Coordinate Plane I can identify and understand equations for circles.

Slides:



Advertisements
Similar presentations
12-5 Circles in the Coordinate Plane
Advertisements

Circles Sheila Roby April 22, What is a circle? A circle is the set of all points in a plane equidistant from a fixed point. Equi means same, so.
Objectives Write equations and graph circles in the coordinate plane.
CIRCLES Unit 3-2. Equations we’ll need: Distance formula Midpoint formula.
Distance and Midpoint Formulas; Circles
[x – (–8)] 2 + (y – 0) 2 = ( 5 ) 2 Substitute (–8, 0) for (h, k) and 5 for r. Write the standard equation of a circle with center (–8, 0) and radius 5.
3.4 Area and Circumference 1 Circle A circle is a plane figure that consists of all points that lie the same distance from a fixed point. The fixed point.
Chapter 1 Functions and Graphs Copyright © 2014, 2010, 2007 Pearson Education, Inc Distance and Midpoint Formulas; Circles.
10.7 Write and Graph Equations of Circles Hubarth Geometry.
Geometry Equations of a Circle.
GeometryGeometry Lesson 75 Writing the Equation of Circles.
Equations of Circles 10.6 California State Standards 17: Prove theorems using coordinate geometry.
EXAMPLE 1 Write an equation of a circle Write the equation of the circle shown. The radius is 3 and the center is at the origin. x 2 + y 2 = r 2 x 2 +
10.6 Equations of Circles Advanced Geometry. What do you need to find the equation of a circle? Coordinates of the Center of the circle. Radius – Distance.
Standard Form for the Equation of the Circle
9-8 Equations of Circles Objectives: To write and use the equation of a circle in the coordinate plane.
GEOMETRY HELP [x – (–8)] 2 + (y – 0) 2 = ( 5 ) 2 Substitute (–8, 0) for (h, k) and 5 for r. Write the standard equation of a circle with center (–8, 0)
Chapter 2 Functions and Graphs Copyright © 2014, 2010, 2007 Pearson Education, Inc Distance and Midpoint Formulas; Circles.
1.8: Perimeter, Circumference, and Area
EXAMPLE 3 Write the standard equation of a circle The point (–5, 6) is on a circle with center (–1, 3). Write the standard equation of the circle. SOLUTION.
Unit 1 – Conic Sections Section 1.2 – The Circle Calculator Required.
Circles in the Coordinate Plane
Section 2.4 – Circles Circle – a set of points in a plane that are equidistant from a fixed point.
Section 9-3 Circles Objectives I can write equations of circles I can graph circles with certain properties I can Complete the Square to get into Standard.
Conics Circle. Circles Circle Circle-The set of all points in a plane at a distance r from a given point called the center. The distance r is the radius.
SWBAT write an equation of a circle (G.12)
GeometryGeometry 10.6 Equations of Circles Geometry.
Find the equation of the line with: 1. m = 3, b = m = -2, b = 5 3. m = 2 (1, 4) 4. m = -3 (-2, 8) y = 3x – 2 y = -2x + 5 y = -3x + 2 y = 2x + 2.
12.4 The Distance Formula Objectives: Use the distance formula to find the distance between 2 points in a coordinate plane. Determine whether a triangle.
Section 6.2 – The Circle. Write the standard form of each equation. Then graph the equation. center (0, 3) and radius 2 h = 0, k = 3, r = 2.
Write and Graph Equations of Circles Chapter 10: Circles.
12.5 Circles in the Coordinate Plane
Algebra II Honors Problem of the Day Homework: p odds Without graphing find all symmetries for each equation.
Equations of Circles. Vocab Review: Circle The set of all points a fixed distance r from a point (h, k), where r is the radius of the circle and the point.
Warm-Up What is the distance between the two trees? If you wanted to meet a friend halfway, where would you meet.
Circles Standard form of a circle: Notice the sign change. When pulling the numbers out of the equation to get the center, change the signs!
1.1 and 1.5 Rectangular Coordinates and Circles Every man dies, not every man really lives. -William Wallace.
11.5: Circles in the Coordinate Plane OBJECTIVES: STUDENTS WILL BE TO… IDENTIFY THE CENTER AND THE RADIUS OF A CIRCLE FROM ITS EQUATION WRITE AND GRAPH.
Circles in the Coordinate Plane
Warm Up. EQUATION OF A CIRCLE Geometry How can we make a circle? What are the most important aspects when drawing a circle?
The Circle. Examples (1) – (5) Determine the center and radius of the circle having the given equation. Identify four points of the circle.
9.6 Circles in the Coordinate Plane Date: ____________.
8.1 The Rectangular Coordinate System and Circles Part 2: Circles.
13.6 Circles. T127 Circle equation: (x-h) 2 + (y-k) 2 = r 2 Where (h,k) is the center of the circle and r = radius.
GeometryGeometry Equations of Circles. GeometryGeometry Finding Equations of Circles You can write an equation of a circle in a coordinate plane if you.
Chapter 10.7 Notes: Write and Graph Equations of Circles
Equations of Circles. You can write an equation of a circle in a coordinate plane, if you know: Its radius The coordinates of its center.
Equation of a Circle. Equation Where the center of the circle is (h, k) and r is the radius.
EXAMPLE 1 Write an equation of a circle Write the equation of the circle shown. SOLUTION The radius is 3 and the center is at the origin. x 2 + y 2 = r.
Equation of Circle Midpoint and Endpoint Distance Slope
Section 2.8 Distance and Midpoint Formulas; Circles.
Holt Geometry 11-7 Circles in the Coordinate Plane 11-7 Circles in the Coordinate Plane Holt Geometry Warm Up Warm Up Lesson Presentation Lesson Presentation.
Then/Now You wrote equations of lines using information about their graphs. Write the equation of a circle. Graph a circle on the coordinate plane.
  Where the center of the circle is (h, k) and r is the radius. Equation.
Warm Up Find the slope of the line that connects each pair of points. – (5, 7) and (–1, 6) 2. (3, –4) and (–4, 3)
10-8 Equations of Circles 1.Write the equation of a circle. 2.Graph a circle on the coordinate plane.
Circles March 18th A ___________ is the set of all point that are a fixed distance, called the _________ from a fixed point, called the _________.
10.3 Circles 10.3 Circles What is the standard form equation for a circle? Why do you use the distance formula when writing the equation of a circle? What.
8.1 The Rectangular Coordinate System and Circles Part 2: Circles.
Circles in the Coordinate Plane
10.6 Equations of Circles Geometry.
Lesson: 10 – 8 Equations of Circles
11.7 Circles in the Coordinate Plane
10-7: Write and Graph Equations of Circles
Chapter 9 Section 8: Equations of Circles.
LT 11.8: Write equations and graph circles in the coordinate plane.
Objectives Write equations and graph circles in the coordinate plane.
Circles in the Coordinate Plane
Equations of Circles Advanced Geometry.
10.7 Write and Graph Equations of ⊙s
Presentation transcript:

Circles in the Coordinate Plane I can identify and understand equations for circles.

X^2 + y^2 = r^2 ► If the circle is in the middle of the coordinate plane, (0,0) then the formula for it is x^2 + y^2 = r^2

(y – 4)^2 – (x - 4)^2 = r^2 If it is not in 0,0, and instead on 4,4, then The formula would look like this: If it is not in 0,0, and instead on 4,4, then The formula would look like this: (y – 4)^2 – (x - 4)^2 = r^2 (y – 4)^2 – (x - 4)^2 = r^2

Where Does the Circle Formula Come From? Using the distance formula, the radius of the circle is represented by: Using the distance formula, the radius of the circle is represented by: = Equation of a circle h and k are the x and y coordinates in the center of the circle.

Example 1 Write the equation for the circle with center at (3,-5) and a radius of 3. Write the equation for the circle with center at (3,-5) and a radius of 3.

Answer Notice how the coordinate of -5 appears as (y+5)^2.

Example 2 Given the equation of the circle (x + 3)^2 + (y – 6)^2 = 24, what are the coordinates of the center and the radius.

Answer The center is (-3,6) and the radius is 24 = 2 6