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RK-83: Scientific Graphing Calculator

iPhone / iPad
  • Utilities
  • Education
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Visit to see video tutorials on powerful RK-83 features!

Don't spend $100+ on an old fashioned graphing calculator. Get all these features (plus more added with every FREE update):

Algebra and Trigonometry:
-Functions for calculating the absolute value, floor, ceiling, gcd, fractional part, integer part, and more
-Nestable functions: gcd(4,gcd(14,6))
-Scientific Notation with 14 digit precision: the highest possible machine level precision for iPhone
-Standard trig functions (sine, cosine, cosecant, secant, cotangent)
-Hyperbolic and inverse trig functions

-Min, max, mean, standard deviation, variance
-Easy to use list syntax: stdDev({1,2,3,2})
-Create custom lists: seq(rand*X,X,1,5)

-Calculate the area under a curve: fnInt(2X, X, 1, 2)
-Find a point derivative: nDeriv(X^2+X, X, 0)
-Solve for zeros: solve(X^2 - 2, X, 1.5)
-Complex number operations: conj(), real(), imag()

Linear Algebra:
-Matrices use built in operators, like "*" for multiplication: [[1,2][3,4]] * [[5,6][7,8]]
-Use built-in functions on matrices: sin({1, 2, 3})
-Get the dimensions of a matrix: dim([[4, 5, 6][7, 8, 9]])

-Email your calculation history
-Get support online at, or email us directly:

The RK-83 grapher is intuitive, powerful, and easy to use. The features you'll love:

-Touchable panning and pinch zooming
-Vibrant multi-colored graphs
-The best graph tracing you've ever seen
-Full screen shots

Version 1.2 is available now! It adds the much requested degree/radian mode! It's faster and more powerful than ever!

New in Version 1.2:
-Create and modify lists: sortA(seq(rand,X,1,10))
-User-defined functions: func(X, X^2)->G
-While loops: while(not(isPrime(X)), X+1->X)
-Degree and radian angle modes (in Settings below the Graph button)
-Quickly adjust your graph scale for "Degree Mode" with the new "ZoomTrig" button
-Faster graphing

Visit for documentation, including video tutorials, sample problems, and function reference.