A set of linear equations is represented by the matrix equation Ax = b...
Necessary Condition for Existence of Solution for Linear Equations
The necessary condition for the existence of a solution for a set of linear equations represented by the matrix equation Ax = b is that A must be invertible.
Explanation:
- Invertible matrix: An invertible matrix is a square matrix that has an inverse, i.e., a matrix that when multiplied with the original matrix gives an identity matrix. A matrix that is not invertible is called a singular matrix.
- Solving linear equations: To solve a set of linear equations, we represent them in matrix form as Ax = b, where A is the coefficient matrix, x is the variable matrix, and b is the constant matrix. The solution to the system of equations is obtained by finding the inverse of A and multiplying it with b, i.e., x = A^-1b.
- Existence of solution: For a solution to exist, the matrix A must be invertible. If A is not invertible, then the system of equations does not have a unique solution. In other words, there are either no solutions or infinitely many solutions.
- Linearly dependent/independent: The linear dependence or independence of b on the columns of A does not affect the existence of a solution. It only affects the uniqueness of the solution. If b is linearly dependent on the columns of A, then there are infinitely many solutions. If b is linearly independent of the columns of A, then there is a unique solution.
Therefore, the correct answer is option 'A' - A must be invertible.
A set of linear equations is represented by the matrix equation Ax = b...
Ans should be D because if A is invertible then solution exist true but when A is non invertible then also infinte solution can exists when b linearly depends on A. another case if b is linearly independent of A then solution exist when A invertible. So none of given condition are necessary
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