Texas Instruments TI-92 Owners Manual - Page 447

cZerosx^5+4x^4+5x^3, cZerosconjz, cZeros{u, u_, v_}, ans1[2]

Page 447 highlights

cZeros() MATH/Algebra/Complex menu cZeros(expression, var) ⇒ list Display Digits mode in Fix 3: Returns a list of candidate real and non-real values of var that make expression=0. cZeros() does this by computing exp8list(cSolve(expression=0,var),var). Otherwise, cZeros() is similar to zeros(). Note: See also cSolve(), solve(), and zeros(). cZeros(x^5+4x^4+5x^3ì 6xì 3,x) ¸ {ë 2.125 ë.612 .965 ë 1.114 ì 1.073ø i ë 1.114 + 1.073ø i} Note: If expression is non-polynomial with functions such as abs(), angle(), conj(), real(), or imag(), you should place an underscore _ (TI-89: ¥  TI-92 Plus: 2  ) at the end of var. By default, a variable is treated as a real value. If you use var_ , the variable is treated as complex. You should also use var_ for any other variables in expression that might have unreal values. Otherwise, you may receive unexpected results. z is treated as real: cZeros(conj(z)ì 1ì i,z) ¸ {1+i} z_ is treated as complex: cZeros(conj(z_)ì 1ì i,z_) ¸ {1ì i} cZeros({expression1, expression2 varOrGuess1,varOrGuess2 matrix Returns candidate positions where the expressions are zero simultaneously. Each varOrGuess specifies an unknown whose value you seek. Optionally, you can specify an initial guess for a variable. Each varOrGuess must have the form: variable - or - variable = real or non-real number For example, x is valid and so is x=3+i. If all of the expressions are polynomials and you do NOT specify any initial guesses, cZeros() uses the lexical Gröbner/Buchberger elimination method to attempt to determine all complex zeros. Complex zeros can include both real and non-real zeros, as in the example to the right. Each row of the resulting matrix represents an alternate zero, with the components ordered the same as the varOrGuess list. To extract a row, index the matrix by [row]. Note: The following examples use an underscore _ (TI-89: ¥  TI-92 Plus: 2 ) so that the variables will be treated as complex. cZeros({u_ù v_ì u_ì v_,v_^2+u_}, {u_,v_}) ¸ 1/2  1/2 ì 23øi + 23øi 1/2 1/2 + ì 2233øøii 0 0  Extract row 2: ans(1)[2] ¸ [ 1/2 + 23øi 1/2 ì 23øi] 430 Appendix A: Functions and Instructions

  • 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
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379
  • 380
  • 381
  • 382
  • 383
  • 384
  • 385
  • 386
  • 387
  • 388
  • 389
  • 390
  • 391
  • 392
  • 393
  • 394
  • 395
  • 396
  • 397
  • 398
  • 399
  • 400
  • 401
  • 402
  • 403
  • 404
  • 405
  • 406
  • 407
  • 408
  • 409
  • 410
  • 411
  • 412
  • 413
  • 414
  • 415
  • 416
  • 417
  • 418
  • 419
  • 420
  • 421
  • 422
  • 423
  • 424
  • 425
  • 426
  • 427
  • 428
  • 429
  • 430
  • 431
  • 432
  • 433
  • 434
  • 435
  • 436
  • 437
  • 438
  • 439
  • 440
  • 441
  • 442
  • 443
  • 444
  • 445
  • 446
  • 447
  • 448
  • 449
  • 450
  • 451
  • 452
  • 453
  • 454
  • 455
  • 456
  • 457
  • 458
  • 459
  • 460
  • 461
  • 462
  • 463
  • 464
  • 465
  • 466
  • 467
  • 468
  • 469
  • 470
  • 471
  • 472
  • 473
  • 474
  • 475
  • 476
  • 477
  • 478
  • 479
  • 480
  • 481
  • 482
  • 483
  • 484
  • 485
  • 486
  • 487
  • 488
  • 489
  • 490
  • 491
  • 492
  • 493
  • 494
  • 495
  • 496
  • 497
  • 498
  • 499
  • 500
  • 501
  • 502
  • 503
  • 504
  • 505
  • 506
  • 507
  • 508
  • 509
  • 510
  • 511
  • 512
  • 513
  • 514
  • 515
  • 516
  • 517
  • 518
  • 519
  • 520
  • 521
  • 522
  • 523
  • 524
  • 525
  • 526
  • 527
  • 528
  • 529
  • 530
  • 531
  • 532
  • 533
  • 534
  • 535
  • 536
  • 537
  • 538
  • 539
  • 540
  • 541
  • 542
  • 543
  • 544
  • 545
  • 546
  • 547
  • 548
  • 549
  • 550
  • 551
  • 552
  • 553
  • 554
  • 555
  • 556
  • 557
  • 558
  • 559
  • 560
  • 561
  • 562
  • 563
  • 564
  • 565
  • 566
  • 567
  • 568
  • 569
  • 570
  • 571
  • 572
  • 573
  • 574
  • 575
  • 576
  • 577
  • 578
  • 579
  • 580
  • 581
  • 582
  • 583
  • 584
  • 585
  • 586
  • 587
  • 588
  • 589
  • 590
  • 591
  • 592
  • 593
  • 594
  • 595
  • 596
  • 597
  • 598
  • 599
  • 600
  • 601
  • 602
  • 603
  • 604
  • 605
  • 606
  • 607
  • 608
  • 609
  • 610
  • 611
  • 612
  • 613
  • 614
  • 615
  • 616
  • 617
  • 618
  • 619
  • 620
  • 621
  • 622
  • 623

430
Appendix A: Functions and Instructions
cZeros()
MATH/Algebra/Complex menu
cZeros(
expression
,
var
)
list
Returns a list of candidate real and non-real
values of
var
that make
expression
=0.
cZeros()
does this by computing
exp
8
list(cSolve(
expression
=0,
var
)
,
var
)
.
Otherwise,
cZeros()
is similar to
zeros()
.
Note:
See also
cSolve()
,
solve()
, and
zeros()
.
Display Digits mode in
Fix 3
:
cZeros(x^5+4x^4+5x^3
ì
6x
ì
3,x)
¸
{
ë
2.125
ë
.612
.965
ë
1.114
ì
1.073
ø
i
ë
1.114
+
1.073
ø
i
}
Note:
If
expression
is non-polynomial with
functions such as
abs()
,
angle()
,
conj()
,
real()
,
or
imag()
, you should place an underscore _
(
TI-89:
¥
²
TI-92 Plus:
2
±
) at the end
of
var
. By default, a variable is treated as a
real value. If you use
var
_
, the variable is
treated as complex.
You should also use
var
_ for any other
variables in
expression
that might have unreal
values. Otherwise, you may receive
unexpected results.
z is treated as real:
cZeros(conj(z)
ì
1
ì
i
,z)
¸
{1+
i
}
z_ is treated as complex:
cZeros(conj(z_)
ì
1
ì
i
,z_)
¸
{1
ì
i
}
cZeros({
expression1
,
expression2
[
,
]
},
{
varOrGuess1
,
varOrGuess2
[
,
]
})
matrix
Returns candidate positions where the
expressions are zero simultaneously. Each
varOrGuess
specifies an unknown whose
value you seek.
Optionally, you can specify an initial guess
for a variable. Each
varOrGuess
must have the
form:
variable
– or –
variable
=
real or non-real number
For example,
x
is valid and so is
x=3+
i
.
If all of the expressions are polynomials and
you do NOT specify any initial guesses
,
cZeros()
uses the lexical Gröbner/Buchberger
elimination method to attempt to determine
all
complex zeros.
Note:
The following examples use an
underscore _ (
TI-89:
¥
²
TI-92 Plus:
2
±
) so that the variables
will be treated as complex.
Complex zeros can include both real and
non-real zeros, as in the example to the right.
Each row of the resulting matrix represents
an alternate zero, with the components
ordered the same as the
varOrGuess
list. To
extract a row, index the matrix by [
row
].
cZeros({u_
ù
v_
ì
u_
ì
v_,v_^2+u_},
{u_,v_})
¸
1/2
ì
3
2
ø
i
1/2 +
3
2
ø
i
1/2 +
3
2
ø
i
1/2
ì
3
2
ø
i
0
0
Extract row 2:
ans(1)[2]
¸
[
]
1/2 +
3
2
ø
i
1/2
ì
3
2
ø
i