Inverse Matrix Calculator - Matrix Inversion Calculator & Adjugate Matrix Calculator
Free inverse matrix calculator & matrix inverse calculator. Calculate the inverse of 2×2 and 3×3 matrices using the adjugate method. Get step-by-step solutions, verify results, and understand matrix inversion with detailed explanations.
Last updated: October 30, 2025
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Inverse Matrix Calculator Features
Formula
A⁻¹ = (1/det) × [[d, -b], [-c, a]]
Fast calculation for 2×2 matrices
Method
A⁻¹ = (1/det) × Adjugate(A)
Full step-by-step process shown
Definition
Adjugate = (Cofactor)ᵀ
Transpose of cofactor matrix
Condition
det(A) ≠ 0
Matrix must have non-zero determinant
Check
A × A⁻¹ = I
Automatic verification included
Includes
All intermediate steps
Learn the matrix inversion process
Quick Example Result
2×2 Matrix: A = [[2, 3], [1, 4]]
Determinant
5
Inverse
[[0.8, -0.6], [-0.2, 0.4]]
How the Inverse Matrix Calculator Works
Our inverse matrix calculator uses the adjugate method to find matrix inverses. The process involves calculating the determinant, finding the cofactor matrix, transposing to get the adjugate, and dividing by the determinant. This method works for any invertible square matrix and provides complete step-by-step solutions.
Matrix Inversion Formula
For 2×2: A⁻¹ = (1/det(A)) × [[a₂₂, -a₁₂], [-a₂₁, a₁₁]]For 3×3 and larger: A⁻¹ = (1/det(A)) × Adjugate(A)Adjugate: Adjugate(A) = (Cofactor(A))ᵀCofactor: Cᵢⱼ = (-1)ⁱ⁺ʲ × det(Minorᵢⱼ)The determinant must be non-zero for the matrix to be invertible. If det(A) = 0, the matrix is singular and has no inverse.
Mathematical Foundation
Matrix inversion is a fundamental operation in linear algebra. An invertible matrix (also called non-singular or regular) has a unique inverse that satisfies A × A⁻¹ = A⁻¹ × A = I, where I is the identity matrix. Inverse matrices are essential for solving systems of linear equations, matrix division, and many other applications.
- A matrix is invertible if and only if its determinant is non-zero
- The inverse of a 2×2 matrix has a simple direct formula
- For 3×3 and larger matrices, the adjugate method is most practical
- Matrix inverses are unique: if A⁻¹ exists, it is the only matrix satisfying A × A⁻¹ = I
- The inverse of a product: (AB)⁻¹ = B⁻¹A⁻¹ (note the reversed order)
- Transpose of inverse: (A⁻¹)ᵀ = (Aᵀ)⁻¹
Applications of Inverse Matrices
Inverse matrices have numerous practical applications:
- Solving Linear Systems: Ax = b → x = A⁻¹b
- Computer Graphics: Transformations, rotations, scaling inverses
- Cryptography: Encryption/decryption algorithms
- Statistics: Covariance matrices, regression analysis
- Engineering: Circuit analysis, control systems, signal processing
- Economics: Input-output models, Leontief models
Sources & References
- Linear Algebra and Its Applications - David C. Lay (5th Edition)Comprehensive textbook on matrix operations and inverses
- Introduction to Linear Algebra - Gilbert Strang (5th Edition)MIT OpenCourseWare classic on matrix theory
- Khan Academy - Matrix Inverses and DeterminantsInteractive lessons on matrix inversion and related concepts
Need help with other matrix operations? Try our determinant calculator or system of equations calculator.
Get Custom Calculator for Your PlatformInverse Matrix Calculator Examples
Given Matrix:
- Step 1: Calculate determinant
- det(A) = 2×4 - 3×1 = 8 - 3 = 5
- Step 2: Apply formula
- A⁻¹ = (1/5) × [[4, -3], [-1, 2]]
Solution:
Inverse Matrix:
Verification: A × A⁻¹ = I ✓
Result: Matrix is invertible with determinant = 5
The inverse exists and can be calculated using the formula above.
3×3 Matrix Example
For 3×3 matrices, use:
1) Find cofactor matrix
2) Transpose to get adjugate
3) Divide by determinant
Singular Matrix
If det(A) = 0:
Matrix is NOT invertible
Rows/columns are linearly dependent
Frequently Asked Questions
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