Lesson
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💻 Solving Simulteneous

Solving Simulteneous.

This lesson covers core applied mathematics concepts and their agricultural applications for BSc Agriculture learners.


MATHS :: Lecture 21 :: Solving simulteneous equation and cramers rule

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INVERSE OF A MATRIX

Definition

Let A be any square matrix. If there exists another square matrix B Such that AB = BA = I (I is a unit matrix) then B is called the inverse of the matrix A and is denoted by A-1. The cofactor method is used to find the inverse of a matrix. Using matrices, the solutions of simultaneous equations are found.

Introduction to Vectors

Vector Transformations

Vector Dot Product and Vector Length

Unit Vectors

Matrix Vector Products

Matrices to solve a vector combination problem

Converting a line from Cartesian to vector form

Working Rule to find the inverse of the matrix Step 1: Find the determinant of the matrix. Step 2: If the value of the determinant is non zero proceed to find the inverse of the matrix. Step 3: Find the cofactor of each element and form the cofactor matrix. Step 4: The transpose of the cofactor matrix is the adjoint matrix. Step 5: The inverse of the matrix A-1 = lec21_clip_image002_0000.gif Example Find the inverse of the matrix lec21_clip_image004_0001.gif Solution Let A =lec21_clip_image004_0002.gif Step 1 lec21_clip_image007_0000.gif Step 2 The value of the determinant is non zero \A-1 exists. Step 3 Let Aij denote the cofactor of aij in lec21_clip_image009_0001.gif lec21_clip_image011_0000.gif lec21_clip_image013_0000.gif lec21_clip_image015_0000.gif lec21_clip_image017_0000.gif lec21_clip_image019_0000.gif lec21_clip_image021_0000.gif lec21_clip_image023_0000.gif lec21_clip_image025_0000.gif lec21_clip_image027_0000.gif Step 4 The matrix formed by cofactors of element of determinant lec21_clip_image009_0002.gif is lec21_clip_image030_0000.gif \adj A = lec21_clip_image032_0000.gif Step 5 lec21_clip_image034_0000.gif = lec21_clip_image036_0000.gif __

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Summary Cheat Sheet

  • Focus on core formulas, definitions, and solved patterns from this lesson.
  • Practice stepwise derivations and numerical substitutions carefully.
  • Connect each concept to practical agricultural problem-solving contexts.

References

1 source

Primary classroom notes and standard BSc Agriculture applied mathematics references.

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