Texas Instruments PLUS TI-89 - Manual (Page 232)

Chapter 12: Additional Graphing Topics 215
12ADDLGR.DOC TI-89/TI-92 Plus: Additional Graphing Tools (English) Susan Gullord Revised: 02/23/01 1:03 PM Printed: 02/23/01 2:15 PM Page 215 of 20
From the Graph screen:
1. TI - 89: 2 ‰
TI - 92 Plus: ‰
and select 5:Horizontal or 6:Vertical . A horizontal or vertical line
and a flashing cursor are displayed on the screen.
If the line is initially displayed on an axis, it may be difficult to
see. However, you can easily see the flashing cursor.
2. Use the cursor pad to move the line to the appropriate position.
Then press ¸.
After drawing the line, you are
still in “line” mode.
¦ To continue, move the cursor
to another location.
¦ To quit, press N.
To draw a tangent line, use the ‡ Math toolbar menu. From the
Graph screen:
1. Press ‡ and select A:Tangent .
2. As necessary, use D and C to select the applicable function.
3. Move the cursor to the
tangent point, and press
¸.
The tangent line is drawn,
and its equation is displayed.
To draw a line through a specified point with a specified slope,
execute the
DrawSlp command from the Home screen or a program.
Use the syntax:
DrawSlp x , y , slope
You can also access DrawSlp from the Graph screen.
1. TI - 89: 2 ˆ
TI - 92 Plus: ˆ
and select 6:DrawSlp . This switches to the Home screen and puts
DrawSlp in the entry line.
2. Complete the command, and
press ¸.
DrawSlp 4,0,6.37
The TI -89 / TI-92 Plus
automatically switches to the
Graph screen and draws the
line.
Drawing a
Horizontal or
Vertical Line
Tip: Use 2 t o move the
cursor in larger increments;
2 B , etc.
Drawing a Tangent
Line
Tip: To set the tangent
point, you can also type its x
value and press
¸ .
Drawing a Line
Based on a Point
and a Slope