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inv
Inverse of a square matrix.
Category: Mathematics > Linear Algebra
Syntax
Y = inv(X)Returns the matrix Y with X*Y = Y*X = I.
Description
A matrix has an inverse only when its determinant is nonzero. inv computes it from an LU factorization. For a nearly singular matrix the result can be inaccurate, and a warning reports a bad condition.
To solve A*x = b, write A\b instead of inv(A)*b: it is faster and more accurate, because it never forms the inverse.
Input arguments
X- Square matrix.
Output arguments
Y- Inverse of
X. For a singular matrix a warning is printed and the result holdsInf.
Example
Regular and singular matrices
inv([1 2; 3 4])
inv([2 0; 0 4])
inv([1 2; 2 4])Output
ans = 2×2
-2.0000 1.0000
1.5000 -0.5000
ans = 2×2
0.5000 0
0 0.2500
ans = 2×2
Inf Inf
Inf Inf
Warning: Matrix is singular to working precision.