Texas Instruments TI-86 - Manual (Page 299)

Chapter 20: A to Z Function and Instruction Reference
287
20ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 287 of 118 20ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 287 of 118
DrEqu(
† GRAPH menu
To enter the ' character for
the Q' variables, use the
CHAR MISC
menu.
DrEqu( xAxisVariable , yAxisVariable , xList , yList , tList )
In DifEq graphing mode, draws the solution to a set of
differential equations stored in the Q' variables
specified by xAxisVariable and yAxisVariable. If
direction fields are off (
FldOff is selected), the initial
values must be stored also.
After the solution is drawn, DrEqu( waits for you to
move the cursor to a new initial value and press b
to draw the new solution.
You then are prompted to press Y (to specify another
initial value) or N (to stop).
For the last-drawn solution, the x , y , and t values
(beginning at their initial values) are stored to xList,
yList
, and tList, respectively.
DrEqu( xAxisVariable , yAxisVariable )
Does not store x , y , and t values for the solution.
In DifEq graphing mode, starting with a ZStd
graph screen:
Q'1=Q2:Q'2= L Q1 b Done
0¶tMin:1¶QI1:0¶QI2 b 0
DrEqu(Q1,Q2,XL,YL,TL) b
Move the cursor to a new initial value.
b
Press N to stop graphing. You can then
examine XL , YL , and TL .
DrInv
GRAPH DRAW menu
DrInv expression
Draws the inverse of expression by plotting x values on
the y-axis and y values on the x-axis.
In Func graphing mode:
ZStd:DrInv 1.25 x cos x b