uTo calculate the focus and length of latus rectum

Example

To determine the focus and length of latus rectum for the parabola X =

 

(Y – 2)2 + 3

 

 

 

Use the following V-Window settings.

 

Xmin = –1,Xmax = 10,

Xscale = 1

 

Ymin = –5,

Ymax = 5,

Yscale = 1

m Conic Graphs

w

bwcwdw6(DRAW)

!5(G-SOLVE) 1(FOCUS) (Calculates the focus.)

!5(G-SOLVE)

5(LENGTH)

(Calculates the length of latus rectum.)

When calculating two foci for an ellipse or hyperbolic graph, press e to calculate the second focus. Pressing d returns to the first focus.

When calculating two vertexes for a hyperbolic graph, press e to calculate the second vertex. Pressing d returns to the first vertex.

Pressing e when calculating the vertices of an ellipse will calculate the next value. Pressing d will scroll back through previous values. An ellipse has four vertices.

5-60