一元三次方程(I)
程式可以計算一元三次方程的實根。
程式編寫日期: 2006年9月20日
程式(127步)
| 1 | ENT | 2. | Kin 1 | 3. | Kin 2 | 4. | Kin 4 | 5. | Kin 6 |
| 6. | ENT | 7. | Kin 3 | 8. | Min | 9. | Kin 5 | 10. | ENT |
| 11. | Kin × 2 | 12. | Kin × 3 | 13. | Kin × 6 | 14. | ENT | 15. | Kin × 1 |
| 16. | 3 | 17. | Kin × 1 | 18. | Kin × 6 | 19. | Kout 5 | 20. | x2 |
| 21. | Kin × 5 | 22. | Kin - 6 | 23. | Kout 6 | 24. | x2 | 25. | Kin × 6 |
| 26. | Kout 1 | 27. | Kin - 3 | 28. | Kout 4 | 29. | Kin × 3 | 30. | 9 |
| 31. | Kin × 3 | 32. | 2 | 33. | Kin ÷ 3 | 34. | X←→K5 | 35. | Kin - 3 |
| 36. | Kout 3 | 37. | R→P | 38. | x2 | 39. | Kin + 6 | 40. | 4 |
| 41. | 9 | 42. | +/- | 43. | 10x | 44. | Kin + 6 | 45. | Kout 6 |
| 46. | x2 | 47. | √ | 48. | Kin ÷ 6 | 49. | √ | 50. | Kin 1 |
| 51. | = | 52. | 3√ | 53. | Kin × 5 | 54. | X←→Y | 55. | ÷ |
| 56. | 3 | 57. | = | 58. | cos | 59. | Kin × 5 | 60 | Kout 3 |
| 61. | + | 62. | X←→K1 | 63. | Kin - 1 | 64. | = | 65. | 3√ |
| 66. | X←→K1 | 67. | 3√ | 68. | Kin + 1 | 69. | 1 | 70. | Kin + 6 |
| 71. | 2 | 72. | Kin ÷ 6 | 73. | Kout 6 | 74. | Kin × 1 | 75. | sin-1 |
| 76. | cos | 77 | Kin × 5 | 78. | Kout 5 | 79. | Kin + 1 | 80. | MR |
| 81. | Kin - 1 | 82. | Kout 4 | 83. | Kin 3 | 84. | Kin ÷ 1 | 85. | Kin ÷ 2 |
| 86. | 3 | 87. | Kin ÷ 1 | 88. | Kout 1 | 89. | Kin 6 | 90. | Kin × 3 |
| 91. | SCI 9 | 92. | RND | 93. | Norm | 94. | Kin 1 | 95. | HLT |
| 96. | MR | 97. | Kin + 3 | 98. | Kout 3 | 99. | Kin × 6 | 100. | X←→K2 |
| 101. | Kin + 6 | 102. | Kout 3 | 103. | x2 | 104. | - | 105. | 2 |
| 106. | +/- | 107. | Kin × 4 | 108. | × | 109. | Kout 4 | 110. | × |
| 111. | Kout 6 | 112. | = | 113. | √ | 114. | Kin + 2 | 115. | Kin - 3 |
| 116. | Kout 4 | 117. | Kin ÷ 2 | 118. | Kin ÷ 3 | 119. | Kout 2 | 120. | SCI 9 |
| 121. | RND | 122. | X←→K3 | 123. | RND | 124. | Kin 2 | 125. | Norm |
| 126. | HLT | 127. | Kout 3 | 128. | 129. | 130. |
LRN 模式輸入程式(供fx-3800P使用，程式長度: 127步)
| ENT 1 | Kin 1 | Kin 2 | Kin 4 | Kin 6 |
| ENT 3 | Kin 3 | Min | Kin 5 | ENT 3 |
| Kin × 2 | Kin × 3 | Kin × 6 | ENT 1 | Kin × 1 |
| 3 | Kin × 1 | Kin × 6 | Kout 5 | x2 |
| Kin × 5 | Kin - 6 | Kout 6 | x2 | Kin × 6 |
| Kout 1 | Kin - 3 | Kout 4 | Kin × 3 | 9 |
| Kin × 3 | 2 | Kin ÷ 3 | X←→K5 | Kin - 3 |
| Kout 3 | R→P | x2 | Kin + 6 | 4 |
| 9 | +/- | 10x | Kin + 6 | Kout 6 |
| x2 | √ | Kin ÷ 6 | √ | Kin 1 |
| = | 3√ | Kin × 5 | X←→Y | ÷ |
| 3 | = | cos | Kin × 5 | Kout 3 |
| + | X←→K1 | Kin - 1 | = | 3√ |
| X←→K1 | 3√ | Kin + 1 | 1 | Kin + 6 |
| 2 | Kin ÷ 6 | Kout 6 | Kin × 1 | sin-1 |
| cos | Kin × 5 | Kout 5 | Kin + 1 | MR |
| Kin - 1 | Kout 4 | Kin 3 | Kin ÷ 1 | Kin ÷ 2 |
| 3 | Kin ÷ 1 | Kout 1 | Kin 6 | Kin × 3 |
| SCI 9 | RND | Norm | Kin 1 | HLT |
| MR | Kin + 3 | Kout 3 | Kin × 6 | X←→K2 |
| Kin + 6 | Kout 3 | x2 | - | 2 |
| +/- | Kin × 4 | × | Kout 4 | × |
| Kout 6 | = | √ | Kin + 2 | Kin - 3 |
| Kout 4 | Kin ÷ 2 | Kin ÷ 3 | Kout 2 | SCI 9 |
| RND | X←→K3 | RND | Kin 2 | Norm |
| HLT | Kout 3 | MODE . |
例題1: 解 2x3 - x2 - 72x + 36 =0
按 P1 再按 2 RUN 1 +/- RUN 72 +/- RUN 36 RUN (顯示第一個根為6)
RUN (顯示第二個根為 0.5) RUN (顯示第三個根為 -6)
例題2: 解 3x3 - 5x2 + x - 4 =0
按 P1 再按 3 RUN 5 +/- RUN 1 RUN 4 +/- RUN (顯示第一個根為1.86977)
RUN (顯示-E-表示其餘兩根為複數根)