OfficeOne 894 Graphic Calculator
From Wikistix
Ok, so, it cost AUD $7, but it looks like you get what you pay for.
Bug 1
Tripped over this when calculating the bond angle in methane, the tetrahedral angle. First, in calculator-like format, with the calculators response at the end:
- Deg:2tan^{-1}√2 = 109.4712206
- Deg:90 + sin^{-1}(3^{-1}) = 109.4712206
- Deg:90 + sin^{-1}(3^{-1}) - 2tan^{-1}√2 = 2e-09
- Deg:sin^{-1}(3^{-1}) + 90 - 2tan^{-1}√2 = 2e-09
- Deg:2tan^{-1}√2 - 90 - sin^{-1}(3^{-1}) = 19.13138372 huh?
Those last three lines should be approximately zero, since [math]2\cdot\arctan \sqrt{2} = 90 + \arcsin \tfrac{1}{3}[/math] but no matter how many parenthesis I put in, that last line refuses to work. Interestingly, switching to radians makes it work:
- Rad:2tan^{-1}√2 - Π÷2 - sin^{-1}(3^{-1}) = -2.4e-11
Bug 2
The random number generator is fine when running interactively, but when run in a tight loop, values tend toward 0 or 1.
Scl:-1000→A:Lbl 0:Ran# dt :Isz A:Goto 0
Let's have a look at some of the statistics variables:
- [math]n = 1000[/math]
- [math]\sum{x} = 598[/math]
- [math]\sum{x^2} = 357.604[/math]
- [math]\bar x = 0.598[/math]
- [math]x\sigma _{n-1} = 0[/math]
Ok, that's unexpected.