Presentation is loading. Please wait.

Presentation is loading. Please wait.

Graphing and Writing Equations

Similar presentations

Presentation on theme: "Graphing and Writing Equations"— Presentation transcript:

1 Graphing and Writing Equations
Circles Graphing and Writing Equations

2 What is a circle? A conic formed when…. A second degree equation…
A locus of points…

3 Definition as a conic A circle is a conic or a conic section because it is formed by the intersection of a plane and a double-napped cone.

4 Algebraic Definition A circle is defined as the second degree equation
Ax2+Bxy+Cy2 +Dx+Ey+F = 0 when A = C.

5 A circle is a locus of points…..
But, what is a locus…? A locus is the set of all points, and only those points, that satisfy one or more conditions. So, “ A locus of points in a plane 10 cm from a point A” gives a geometric description of a circle with center A and a radius of 10

6 Geometric Definition A circle is the locus or collection of all points (x, y) that are equidistant from a fixed point, (h, k) called the center of the circle. The distance r , between the center and any point on the circle is the radius

7 Using the distance formula, you can derive
the standard form of a circle. (x- h)2 + (y- k)2 = r 2 where, center = (h, k) and radius = r

8 Equation of a circle: Practice Problems to write the equation of a circle when given the center and the radius.

9 What if the center and radius are not given?
Try these : Center = (0,3) and solution point = (0, 6) Endpoints of diameter are (-2,3) and (6,5) Center on the line y = 2, and tangent to the x-axis at (3,0)

10 Graph the circle To graph a circle, locate all the points that are a fixed distance r, from the center (h, k). Click here to graph a circle

11 Graph a circle with center at the origin
Example: Graph x2 + y2 = 4

12 To Graph a Circle center (h,k) and radius r
Example: (x-3)2+   (y-3)2 =4 Click Here To graph a circle if given a radius and a center

13 What are some applications?
Circular orbits of the earth for satellites. Perfect shape for cross-section of a submarine. Gears Other

Download ppt "Graphing and Writing Equations"

Similar presentations

Ads by Google