Texas Instruments TI-82 User Manual - Page 116

Drawing Tangent Lines

Page 116 highlights

Drawing Tangent Lines While a graph is displayed, you can draw the tangent line of a function at a specified point using the cursor. If a graph is not displayed, the instruction is copied to the Home screen. Directly on a Graph 1. When a graph of selected functions is displayed, select Tangent( from the DRAW DRAW menu (item 5). 2. Use † and } to move the cursor to the function for which you want to draw the tangent line. 3. Use ~ and | to move the cursor to the point on the function at which you want to draw the tangent line. 4. Press Í. From the Home Screen or a Program Tangent( (tangent line) (DRAW DRAW item 5) draws a line tangent to an expression in terms of X (such as Y1 or X2) at point X=value (which can be an expression). expression is interpreted as being in Func MODE. Tangent(expression,value) For example, if Y1=.2X3-2X+6 is the only selected function, Tangent(Y1,3) plots Y1 and draws the tangent to the function at X=3: 8-6 DRAW Operations

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278

8-6
DRAW
Operations
Drawing Tangent Lines
While a graph is displayed, you can draw the tangent line of a function at a
specified point using the cursor. If a graph is not displayed, the instruction is
copied to the Home screen.
Directly on a Graph
1.
When a graph of selected functions is displayed, select
Tangent(
from
the
DRAW DRAW
menu (item
5
).
2.
Use
and
}
to move the cursor to the function for which you want to
draw the tangent line.
3.
Use
~
and
|
to move the cursor to the point on the function at which
you want to draw the tangent line.
4.
Press
Í
.
From the Home Screen or a Program
Tangent(
(tangent line) (
DRAW DRAW
item
5
) draws a line tangent to an
expression
in terms of
X
(such as
Y
1
or
X
2
) at point
X
=
value
(which can be
an expression).
expression
is interpreted as being in
Func
MODE
.
Tangent(
expression
,
value
)
For example, if
Y
1
=.2X
3
–2X+6
is the only selected function,
Tangent(Y
1
,3)
plots
Y
1
and draws the tangent to the function at
X
=3: