Notebook Calculator vs Random Letter

DOING LONG CALCULATIONS IN NOTEBOOK ! GO BACK & CHANGE ERRORS EASILY ! JUST LIKE TYPE IN A TEXT FIELD ! COPY + CUT + PASTE EDIT & SAVE CALCULATION HISTORY ! SCIENTIFIC & GRAPHIC CALCULATOR ! • It Supports the File Management ! - Create a file - Save - Open - Delete • Mathematical Functions: SIN(X) : sine of x COS(X) : cosine of x TAN(X) : tangent of x COT(X) : cotangent of x ASIN(X) : arcsine of x ACOS(X) : arccosine of x ATAN(X) : arctangent of x SINH(X) : hyperbolic sine COSH(X) : hyperbolic cosine TANH(X) : hyperbolic tangent ASINH(X) : inverse hyperbolic sine ACOSH(X) : inverse hyperbolic cosine ATANH(X) : inverse hyperbolic tangent SQRT(X) : square root of x ABS(X) : absolute value of x FCT(X) : x factorial LOG(X,Y) : logarithm of y to base x LN(X) : natural logarithm of x LOG(X) : base-10 logarithm of x LOG10(X) : base-10 logarithm of x LOG2(X) : base-2 logarithm of x EXP(X) : base-e exponential of x ERF(X) : the error function of x ERFC(X) : the complementary error function of x ROUND(X) : integral nearest to x CEIL(X) : the smallest integral that is not less than x FLOOR(X) : the largest integral that is not greater than x TGAMMA(X) : the gamma function of x LGAMMA(X) : the natural logarithm of the absolute value of the gamma function of x X^Y : y-th power of x • Statistical functions: SUM(a1,a2,a3,a4) : a1+a2+a3+a4 AVERAGE(a1,a2,a3,a4) : (a1+a2+a3+a4)÷4 VARIANCE(a1,a2,a3,a4) : variance SD(...) : standard deviation SUMSQ(...) : sum of squares AD(...) : absolute deviation CV(...) : coefficient of variation SVARIANCE(...) : sample variance SSD(...) : sample standard deviation SCV(...) : sample coefficient of variance • Help Manual: “//” means a line comment or annotation. A=2 B=3 C=A+B Click “Run”, the screen shows: C=5 If the line C=A+B is annotated , A=2 B=3 //C=A+B Click “Run”, the screen shows: B=3 - Variable Naming Rules: Start with letters, and not involving keywords. A, A1, B25, HAT (right) PRINT1, COS (wrong) - The Usage of PRINT: A=10+5 B=10/5 PRITN A,B Click “Run”, the screen shows: A=15 B=2 Default variable name is RESULT , e.g. 16+5*6 Click “Run”, the screen shows: RESULT=46 - Combination & Arrangement: C(n,k) = n!/(k!(n-k)!) A(n,k) = n!/(n-k)! - Complex Number When there is “i” or “∠” on the screen, it automatically enters Complex Number Calculation Mode. e.g. X=3+4i or X=5∠53.1° 9 functions are available for the Mode. SIN(X), COS(X), TAN(X) COT(X), SINH(X), COSH(X) SQRT(X), ABS(X), CONJUGATE(X) - Integral INTEGRAL X²,2,4 Default precision is 300 times of calculations. It can be more accurate, e.g. 500 times. INTEGRAL X²,2,4,500 - Graphics PLOT SIN(X) PLOT X² Default length = 10, width = 10. Specify the lenght = 20, width = 5. Then we have, PLOT X²,20,5 Default dense is 150 points. It also can be customized, e.g. 200 points. PLOT X²,20,5,200

This app shows random letters from English Alphabet. -can show only vowels -can show only consonants -full screen letters, so it's good too use the app in a company of kids or friends. -configurable min and max value. Default range is from A to Z. -letter is refreshed using touch/click. -a dark color scheme for the UI to save battery power of your device. -applicable for all age groups. Enjoy!