Calculator Forensics Results for the Equation arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) ) (evaluated in degrees mode) --- This dataset lists the computed result of the above complex trigonometric expression on various calculator models, sorted by the result value. The results reveal variations and approximations in calculator math implementations. --- Summary of Key Results Result = 0.0 A number of early or certain vacuum fluorescent display (VFD) and LED calculators produce zero: APF Mark 50, 51, 88 (with General Instruments CF596 chipset) Conic 980 (VFD) Electronika B3-32, Elektronika MKSCH-2, MKU-1 (VFD) Lloyd's Accumatic 334 (VFD) Omron 86SR (VFD) Radio Shack EC-475 (LED) Sinclair Oxford 300 Unisonic 796 (with General Instruments CF596) Result ≈ 6.58 Various Elektronika models and some Rockwell chipset calculators fall here: Aristo M 85 (8+2 digit LED) Elektronika B3-35, B3-36, MK-35, MK-36, MK-45, MK-66 Result ≈ 8.84 Some RPN calculators including Microcifra 10, Novus 3500, National Semiconductor models, Unitrex 90SC. Result ≈ 8.98 to 9.0 Majority of models including many Casio, Sharp, TI, HP, Radio Shack, Canon, Aurora, Citizen models report values very close to 9, with slight variations in the last decimals depending on precision or chipset. Result ~9.0 to 9.00001+ High precision calculators and modern models typically return values close or equal to 9.0 with minimal floating-point or rounding differences. Many use ARM processors or updated chips. Special Cases Certain calculators like Tamaya NC-2 and NC-77 give an error. Some models produce different results depending on display mode (EXP vs FLOAT). For example, Omron 10SR, Sharp PC-1001. --- Notes Generic 56 function scientific calculators share internals and show consistent results despite branding differences. Polynomial approximations are often used in computing trig functions. Some calculators handle arcsin differently in degrees mode for this complex formula requiring special evaluation. Floating point calculators (like certain Palm OS or Psion devices) might deviate slightly due to using true floating point instead of BCD. Various changes in the last decimal places often relate to different processor chips or firmware versions. --- Data Sources and Contributors Contributions from numerous individuals and sources are documented, among them Viktot Toth, Joerg Woerner, Bob Patton, Katie Wasserman, Dennis Belillo, and many others, indicating a wide-spanning community effort in compiling calculator behavior data. --- Abbreviations CRT: Cathode Ray Tube LCD: Liquid Crystal Display LED: Light Emitting Diode Pnx: Burroughs Panaplex II display VFD: Vacuum Fluorescent Display --- Summary: The evaluation of a nested trigonometric formula on various calculators exhibits a wide range of results due to differences in calculator architecture, math library implementations, chipset, and display precision. The majority of modern scientific calculators return values extremely close to 9, aligning closely with theoretical expectations, while older or simpler models show varied results including zero or errors.