CUET Preparation Today
The system AX = B of n equations in n unknowns has infinitely many solutions if |
det A ≠ 0 det A = 0, (adj A)B ≠ O det A = 0, (adj A)B = O det A ≠ 0, (adj A)B = O |
det A = 0, (adj A)B = O |
X = A–1B $X=\frac{(adj~A) . B}{|A|}$ Clearly if the system has infinite solutions |A| = 0 and (adj A)B = O Hence (3) is the correct answer. |
