Texas Instruments TI-89 Titanium Graphics Calculator (On Sale!)

Functions:

• Real and complex numeric results
• Symbolic manipulation for algebra, calculus and differential equations
• Numeric evaluation of functions in tables and data variable format
• Interactive analysis of function values, roots, maximums, minimums, integrals, derivatives, intersecions, inflection points, and arc lengths
• Recursively-defined sequences access any number of previous terms
• Slope and direction fields for exploring differential equations
• List-based one- and two-variable statistical analysis, including eight regression models
• Statistics plots including scatter, xy-line, box, and modified box plots
• Histograms and regression lines
• Matrix operations including inverse, determinant, transpose, augment, elementary row operations, and reduced row echelon form
• Matrix elements can be real or complex and numeric or symbolic
• Column-logic expressions in data/matrix editor are retained for automatic recalculation when values change
• Hexadecimal and binary operations and conversions

Differential Equations:
• Exact symbolic solutions of many 1st- and 2nd-order ordinary differential equations
• Solve single or systems of differential equations using Euler or Runga Kutta methods
• Graph slope fields or direction fields

Linear Algebra:
• Eigenvalues
• Eignevectors
• Functions of matrices (like e A)
• LU or QR decompistions