E-CodeSeries partial sums, exact — a TI-89 Titanium program
SERIES89 is a TI-89 BASIC program for the TI-89 Titanium. Type the term a(k) as text and the range of k: the exact partial sum (a fraction when the terms are rational), its decimal value, and the ratio |a(n+1)/a(n)| as a hint for convergence.
What it asks for and what it shows
It asks for 3 values at its prompts. In the example below it shows DECIMAL, RATIO, SUM.
Example run
One of its oracle test cases: “Σ 1/k² to 10”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 1/k^2 |
| Input 2 | 1 |
| Input 3 | 10 |
| The screen shows | |
DECIMAL= | 1.549767731 |
RATIO= | 0.826446281 |
SUM= | 1968329/1270080 |
How it's checked
4 test cases, each checked against an independent method. Replayed key by key on a virtual TI-89 Titanium, they make 18 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-89 Titanium calculator and pick “Series partial sums, exact” (SERIES89).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Quadratic roots, exact when possible
- Linear system, exact answers
- LU decomposition with pivoting (exact)
- Matrix inverse, exact
- Trapezoid and Simpson vs nInt
All TI-89 Titanium math programs · All TI-89 Titanium programs