Inverse Matrix - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: Inverse Matrix (/thread-4248.html) Inverse Matrix - Lin Su - 06-28-2015 05:01 AM Hi = )! When i calculate the inverse matrix, i use inv(Matrix) and for small numbers(img.1), there`s no problem but when i try to calculate using large number(img.2)..it shows wrong result.. what am i doing wrong? RE: Inverse Matrix - salvomic - 06-28-2015 06:27 AM (06-28-2015 05:01 AM)Lin Su Wrote:  Hi = )! When i calculate the inverse matrix, i use inv(Matrix) and for small numbers(img.1), there`s no problem but when i try to calculate using large number(img.2)..it shows wrong result.. what am i doing wrong? large number is the image (2?) with [[4,5][6,7]]? its inverse is [[-3.5,2.5][3,-2]], correct. Or am I missing something? Salvo RE: Inverse Matrix - Joe Horn - 06-28-2015 08:17 AM (06-28-2015 05:01 AM)Lin Su Wrote:  Hi = )! When i calculate the inverse matrix, i use inv(Matrix) and for small numbers(img.1), there`s no problem but when i try to calculate using large number(img.2)..it shows wrong result.. what am i doing wrong? (06-28-2015 06:27 AM)salvomic Wrote:   (06-28-2015 05:01 AM)Lin Su Wrote:  Hi = )! When i calculate the inverse matrix, i use inv(Matrix) and for small numbers(img.1), there`s no problem but when i try to calculate using large number(img.2)..it shows wrong result.. what am i doing wrong? large number is the image (2?) with [[4,5][6,7]]? its inverse is [[-3.5,2.5][3,-2]], correct. Or am I missing something? Salvo The images are displayed on the forum web page in reverse order. By "img.2" he means the image on the left. Lin: I typed your 5×5 matrix into my Prime, and it gets the correct inverse both in Home and in CAS. Could there be a typo in your input? RE: Inverse Matrix - DrD - 06-28-2015 09:17 AM With the Excel matrix entered into M6, my results agree with Joe's, (I get the correct inverted values). Just for fun, notice the precision difference between inv(inv(M6)) function value, and (M6^-1)^-1. Using the exponential form returns the original M6, while the inv() function returns a little less precision. -Dale- RE: Inverse Matrix - Lin Su - 06-29-2015 10:28 PM Hi Again X) Thanks !! it was my typing mistake. You were right!!! . Salvomic, Joe Horn, DrD.. For give me for "stealing" your time = ( and Thanks again! RE: Inverse Matrix - salvomic - 06-29-2015 10:33 PM (06-29-2015 10:28 PM)Lin Su Wrote:  Hi Again X) Thanks !! it was my typing mistake. You were right!!! . Salvomic, Joe Horn, DrD.. For give me for "stealing" your time = ( and Thanks again! never mind, we are glad to help you! :-) ciao