Circles Sheila Roby April 22, 2003. What is a circle? A circle is the set of all points in a plane equidistant from a fixed point. Equi means same, so.

Slides:



Advertisements
Similar presentations
Objectives Write equations and graph circles in the coordinate plane.
Advertisements

Advanced Algebra Trigonometry Appendix B
2.2 Parallel and Perpendicular Lines and Circles Slopes and Parallel Lines 1. If two nonvertical lines are parallel, then they have the same slopes. 2.
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.
Circles Lesson Describe what each of the following equations make: 1.y = 4 2.3x + 2y = x 2 – 6x + 12 = 0 4.x 2 + y 2 = 9 1.Horizontal line.
Definition: A circle is the set of all points on a plane that is a fixed distance from the center.
Homework: p ,3,7,15,19 21,27,31,33,37,41,43,49,53,55,57.
Chapter 1 Functions and Graphs Copyright © 2014, 2010, 2007 Pearson Education, Inc Distance and Midpoint Formulas; Circles.
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.
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
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)
Sullivan Algebra and Trigonometry: Section 2.4 Circles Objectives Write the Standard Form of the Equation of a Circle Graph a Circle Find the Center and.
1.8 Circles.
College Algebra 1.9 Circles. Objectives Write the standard form of the equation of a circle. Graph a circle by hand and by using the calculator. Work.
Chapter 2 Functions and Graphs Copyright © 2014, 2010, 2007 Pearson Education, Inc Distance and Midpoint Formulas; Circles.
Unit 1 – Conic Sections Section 1.2 – The Circle Calculator Required.
Circles in the Coordinate Plane I can identify and understand equations for circles.
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.
Section 1.5: Circles Definition circle: Set of points a fixed distance from a center point. Definition radius: Distance from center to any point.
Chapter 1 Functions and Graphs Copyright © 2014, 2010, 2007 Pearson Education, Inc Distance and Midpoint Formulas; Circles.
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.
Algebra II Honors Problem of the Day Homework: p odds Without graphing find all symmetries for each equation.
Warm-Up Find the distance and the midpoint. 1. (0, 3) and (3, 4)
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.
8.3: Circles Write equations of circles Graph circles.
Lesson 9.1 Page #1, 3, 7-19 (ODD), (EOO),35, (ODD), (EOO), (EOO), 83, 85, 91.
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.
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.
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.
Geometry Honors Section 9.6 Circles in the Coordinate Plane.
Circles Ch10.3 and additional material. Geometric Definition: The intersection of a cone and a plane.
Equation of a Circle. Equation Where the center of the circle is (h, k) and r is the radius.
Hyperbolas Objective: graph hyperbolas from standard form.
Graphing Circles and Writing Equations of Circles.
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.
Circles A review?. Let's review what we already know about circles. Definition: A circle is a locus (set) of points in a plane equidistant from a fixed.
  Where the center of the circle is (h, k) and r is the radius. Equation.
Advanced Algebra H Notes Section 9.3 – Graph and Write Equations of Circles Objective: Be able to graph and write equations of circles. A _________ is.
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 _________.
8.1 The Rectangular Coordinate System and Circles Part 2: Circles.
Equations of Circles.
Circles in the Coordinate Plane
Equations of Circles.
Lesson: 10 – 8 Equations of Circles
Circles 4.1 (Chapter 10). Circles 4.1 (Chapter 10)
Equations of Circles.
Circles in the Coordinate Plane
10-7: Write and Graph 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.
The equation of a circle is based on the Distance Formula and the fact that all points on a circle are equidistant from the center.
Circles in the Coordinate Plane
Circles in the Coordinate Plane
Warmup Find the distance between the point (x, y) and the point (h, k).
Warmup Find the distance between the point (x, y) and the point (h, k).
Presentation transcript:

Circles Sheila Roby April 22, 2003

What is a circle? A circle is the set of all points in a plane equidistant from a fixed point. Equi means same, so equidistant means the same distance. The fixed point is called the center. equi fixed point

Equation of a circle Use the distance formula to determine the equation of a circle (h, k) (x, y)

Parameters of circle Center: (h,k) Center: (h,k) The fixed point described in the definition of a circle The fixed point described in the definition of a circle Radius: r Radius: r The distance from the center of the circle to any point on the circle The distance from the center of the circle to any point on the circle r (h,k)

Given the graph of a circle, state its equation Use the center and the point (4,4) to find the radius. Use the center and the point (4,4) to find the radius. (2, 1) (4, 4) To write the equation of a circle you must know the center and the radius. To write the equation of a circle you must know the center and the radius. From our graph we see that the center is at (2,1). From our graph we see that the center is at (2,1).

Given the graph of a circle, state its equation (2, 1) (4, 4) Center (2,1)

Given the equation of a circle, graph it. r 2 = (x -h) 2 +(y-k) 2 Center: (-2,1) Radius: 2 (-2,1) Start at the point (-2,1). Since the radius is 2, go 2 in each direction and draw a point. Connect these points to form the circle.

Sources My memory My memory