4-3-5

Drawing a Conics Graph

kDrawing a Circle by Specifying the Coefficients of a General Equation

Example: To draw the circle x2 + y2 + 4x – 6y + 9 = 0

u ClassPad Operation

(1)In step (2) of the procedure under “Drawing a Circle by Specifying a Center Point and Radius”, select “AX2 + AY2 + BX + CY + D = 0”.

(2)Substitute the following values for the coefficients: A = 1, B = 4, C = –6, D = 9.

Drawing an Ellipse

You can draw an ellipse by specifying coefficients for the standard equation: (x – H)2 (y – K)2

+= 1.

A2B2

Example: To draw the ellipse

(x – 1)2

+

(y – 2)2

= 1

22

32

 

u ClassPad Operation

(1) On the Conics Editor window, tap q, or tap [Form] and then [Insert Conics Form].

• This displays the Select Conics Form dialog box.

(2) Select “(X – H)2 + (Y – K)2 = 1” and then tap [OK].

A2B2

•This closes the Select Conics Form dialog box, and displays the selected equation in the Conics Editor window.

(3)Change the coefficients of the equation as follows: A = 2, B = 3, H = 1, K = 2.

(4)Tap ^ to graph the equation.

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