Eddie's Math and Calculator Blog

 HP Prime:  Linear Exponential Combination Fit The program LINEXPREG attempts to fit bivariate data to the curve: y = a + b * x + c * e^x Th...

 Review:  Ativa 2-Line Calculator DD-2361 Just the Facts: Model:  DD-2361 (I was stated in the manual) Company: Ativa (Office Depot) Type: F...

Heron's Formula vs Area by Vertices There are several ways to determine the area of a triangle. Heron's Formula: With side lengths A...

 Numworks:   3 x 3 Matrices The script invthree.py calculates the inverse and determinant of a 3 x 3 matrix.   Matrices: [[ a1,  a2,  a3 ] [...

 HP 41C and DM41: Operations by Test, Messages, Block Storage   The programs are inspired from a great calculator resource, "Calculator...

 HP Prime:  The Percent Function The Percent Function The HP Prime has three percent functions.   They are not easily found (through the cat...

 HP Prime: Approximate of a Quartic Root Introduction In the article "Square Root & Cube Root Algorithms" (see source below), ...

 Book Review: Calculus for Middle Schoolers by Serena Swegle Just The Facts Calculus for Middle Schoolers Author:  Serena Swegle Publisher: ...

Breaking Down the Factorial Factorial: It's Not Just For Integers Let n be a positive number, where n > 0.   n! can be rewritten as: ...

 Swiss Micros DM41X: Custom Menus Customize It With the new Swiss Micros DM41X, custom menus comes to the HP 41C engine.   The custom menu c...

 HP 42S/DM42/Free42:  Drawing Lines and Circles Introduction The HP 42S, Swiss Micros DM42, and Free42 has several graphics commands that al...

 HP 42S/DM42:  Height of a Fire, Time to Clear a Corridor HP 42S/DM42/Free42 Program:  FIREHGT The program FHGT approximates the height of a...

Review:  Catiga CS-121 Just the Facts: Model:  CS-121 (could be other model numbers) Company: Catiga Type: Graphing Battery:  Case contains ...

 HPCC 2020 Virtual Conference and Document Website  HPCC 2020 Virtual Conference The HPCC 2020 Virtual Conference took place on October 10, ...