My Math Forum Computation of matrix inverse: I + A

 Linear Algebra Linear Algebra Math Forum

 November 10th, 2015, 11:01 PM #1 Newbie   Joined: Jan 2014 Posts: 10 Thanks: 0 Computation of matrix inverse: I + A Let I be the identity matrix, and A be an invertible matrix. Suppose A^(-1) is given. How can we cheaply compute (A + I)^(-1) Can you help me find the right identity. Thank you so much in advance.
 November 11th, 2015, 11:59 AM #2 Banned Camp   Joined: Mar 2015 From: New Jersey Posts: 1,720 Thanks: 126 Solve (A+I)B=I for B For 1X1 matrix solve (a+1)b=1. It has no simple solution in terms of 1/a so OP is not generally solvable. Thanks from topsquark
 November 12th, 2015, 05:05 AM #3 Newbie   Joined: Jan 2014 Posts: 10 Thanks: 0 Hi. I can't see how (A+I)B = I makes computation of (A+I)^(-1) cheaper. How do i exploit that that A^(-1) is known? Thanks in advance

 Tags computation, inverse, matrix

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post question Algebra 1 April 7th, 2012 08:56 AM lambysparks Algebra 0 October 29th, 2011 08:51 AM george gill Calculus 1 May 19th, 2011 10:58 AM RMG46 Linear Algebra 1 July 5th, 2010 05:07 PM ced Linear Algebra 1 October 29th, 2009 04:19 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top