Mathematics 2004 JAMB Past Questions - Question 22: The inverse of the matric (2 1)is1 ; 1

Correct Answer

D

Explanation

The given matrix is (2 1).To find the inverse of a 2x2 matrix, we can use the formula:A^(-1) = (1 / (ad - bc)) * (d -b)                      (-c a)In this case, a = 2, b = 1, c = 1, and d = 0.Calculating the determinant (ad - bc):Determinant = (2 * 0) - (1 * 1) = 0 - 1 = -1Now, we can substitute the values into the formula:A^(-1) = (1 / (-1)) * (0 - 1)                      (-1 2)Simplifying:A^(-1) = -1 * (-1)              (-1 2)A^(-1) = (1)              (-1 2)Therefore, the inverse of the matrix (2 1) is (1)                                                                (-1 2).