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महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Find the inverse of the following matrix. [2-3-12] - Mathematics and Statistics

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प्रश्न

Find the inverse of the following matrix.

`[(2, -3),(-1, 2)]`

Find the inverse of matrix A by elementary row transformations, where A = `[(2, -3),(-1, 2)]`

बेरीज

उत्तर

Let A = `[(2, -3),(-1, 2)]`

∴ |A| = `[(2, -3),(-1, 2)]` = 4 − 3 = 1 ≠ 0

∴ A−1 exists.

Consider AA−1 = I

∴ `[(2, -3),(-1, 2)]`A−1 = `[(1, 0),(0, 1)]`

By R1 + R2, we get,

`[(1, -1),(-1, 2)]`A−1 = `[(1, 1),(0, 1)]`

By R2 + R1, we get,

`[(1, -1),(0, 1)]`A−1 = `[(1, 1),(1, 2)]`

By R1 + R2, we get,

`[(1, 0),(0, 1)]`A−1 = `[(2, 3),(1, 2)]`

∴ A−1 = `[(2, 3),(1, 2)]`

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पाठ 2: Matrics - Exercise 2.2 [पृष्ठ ५२]

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