Math Problem Statement

Solve for the matrix X if A X (D + B X)^{-1} = C. Assume that all matrices are n x n and invertible as needed.

Solution

We are tasked with solving for the matrix XX in the equation:

AX(D+BX)1=CA X (D + B X)^{-1} = C

Assume all matrices are n×nn \times n and invertible where necessary.

Step-by-Step Solution:

  1. Multiply both sides by (D+BX)(D + BX) from the right: To eliminate the inverse, multiply both sides of the equation on the right by D+BXD + BX: AX(D+BX)1(D+BX)=C(D+BX)A X (D + B X)^{-1}(D + BX) = C (D + BX) Simplifying the left-hand side: AX=C(D+BX)A X = C (D + BX)

  2. Expand the right-hand side: Distribute CC over (D+BX)(D + BX): AX=CD+CBXA X = C D + C B X

  3. Group the terms with XX: Move the term with XX on the right-hand side to the left-hand side: AXCBX=CDA X - C B X = C D Factor out XX on the left-hand side: (ACB)X=CD(A - C B) X = C D

  4. Solve for XX: Assuming ACBA - C B is invertible, multiply both sides by (ACB)1(A - C B)^{-1} from the left: X=(ACB)1CDX = (A - C B)^{-1} C D

Final Expression for XX:

X=(ACB)1CDX = (A - C B)^{-1} C D

Would you like further details or clarification on any step? Here are some related questions:

  1. How do we determine if ACBA - CB is invertible?
  2. What if ACBA - CB is not invertible? How would the solution change?
  3. Can this method be generalized to other matrix equations involving inverses?
  4. How would the process differ if BB or DD were non-square matrices?
  5. What real-world applications might involve solving matrix equations like this?

Tip: When working with matrix inverses, always ensure that the matrix in question is invertible by checking its determinant or other criteria for non-singularity.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Matrix Algebra
Matrix Inversion
Linear Equations

Formulas

AX(D + BX)^{-1} = C
X = (A - CB)^{-1}CD

Theorems

Properties of Inverses
Distributive Property of Matrix Multiplication

Suitable Grade Level

College Level