Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
Numbers of Arithmetic Operations To Compute: (x^T)*(A^-1)*x

Subject: Numbers of Arithmetic Operations To Compute: (x^T)*(A^-1)*x

From: Ashley Daly

Date: 18 Feb, 2009 17:09:02

Message: 1 of 1

I'm not sure if anyone here will be able to help with this question, but I thought it was worth a shot.

Let A be a nxn real symmetric positive definite matrix and x not equal to 0 a real nx1 vector. Show how to compute (x^T)*(A^-1)*x in (n^3)/3 + O(n^2) arithmetic operations.

What I tried doing was setting Ax = b, and then finding out what (x^T)*(A^-1)*x is. However, I'm not sure if that is the right thing to do or how that tells me how many operations there are.

I know that we learned that Cholesky requires (n^3)/3 + O(n^2) arithmetic operations, and I'm not even sure of why that is or how you show that.

Does anyone have any ideas? Thank you so much.

Tags for this Thread

No tags are associated with this thread.

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us