Welcome to version 0.9a of RK-89.

RK-89 is the latest release in the most advanced graphing calculator suite available on the App Store. RK-89 introduces symbolic calculation features to the RKalk engine that already powers RK-83.

We're dedicated to making sure your experience with RK-89 is absolutely unprecedented. This early release gives you access to the powerful new features offered by RK-89 and allows us to gather the crucial user feedback we need to keep RK-89 on the cutting edge. Count on the same fast-paced development schedule that thousands of RK-83 users already enjoy; expect updates as quickly as the App Store approval process allows.

The already robust RKalk libraries include:
- numerical integration and solvers
- list and matrix manipulation
- descriptive statistics
- trigonometric and other standard math functions

RK-89 version 0.9a builds on this rock-solid foundation, adding these math and programming features:
- conditions, loops, and boolean operators.
- list creation. `seq(expression, variable, low, high, [step])`
"seq(X^2,X,0,5)" ==> "{0,1,4,9,16}"
- anonymous functions. `func(variable, value expression)`
"func(X,Y,X+Y)->G", "G(3,5)" ==> "8"
- symbolic integration. `integrate(expression, variable)`
"integrate(X^2, X)" ==> "(1/3)x^3"
- symbolic derivatives. `deriv(expression, variable)`
"deriv(X^2, X)" ==> "2x"

Version 1.0 will include arbitrarily precise calculation, symbolic limits, extensions to the existing programming interface, expanded symbolic calculus and statistics routines, and more.

We need your feedback to keep improving RK-89. Tell us what you think.

contact@rkalk.com