5-11-18

Function Analysis

uTo calculate the focus, vertex and length of latus rectum

 

[G-SLV]-[FOCS]/[VTX]/[LEN]

Example

To determine the focus, vertex 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

mCONICS

w

bwcwdw6(DRAW)

!5(G-SLV)

1(FOCS)

(Calculates the focus.)

!5(G-SLV)

4(VTX)

(Calculates the vertex.)

!5(G-SLV)

5(LEN)

(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.

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