E-CodeEngineering on a TI-89: how-to guides
5 guides for engineering on the TI-89 Titanium. Each one shows the keys to press, step by step.
The guides
- Convert a number to binary: Type the number, press 2nd 5 for MATH, ▲ to Base (the last item) and ▶ to open it, then 1 for ▶Bin and ENTER: 256▶Bin gives 0b100000000.
- Multiply complex numbers for AC circuits: Type the complex numbers with 2nd CATALOG for ί and press ENTER: (3.+4.ί)*(1.-2.ί) gives 11.-2.·ί.
- Solve simultaneous equations with a matrix: Type simult( (2nd ALPHA locks letters), the coefficient matrix, a comma and the column of right sides, then ENTER: for x+y=5 and x-y=1, simult([[1,1][1,-1]],[[5][1]]) gives [[3][2]], so x = 3 and y = 2.
- Find the eigenvalues of a matrix: Type eigVl( (2nd ALPHA locks letters), the square matrix with 2nd , for [ and 2nd ÷ for ], close with ) and press ENTER: eigVl([[4,1][2,3]]) gives {5.
- Solve an RC circuit with a differential equation: Press F3, ALPHA ) for deSolve(, type y′+y/2=0 (2nd = types ′; 2 is R·C), add and from 2nd 5 Test and the start value y(0)=5, then t, y and ENTER: y=5·ℯ^(-t/2), the capacitor's voltage over time.