Q. Consider this matrix:[56−3−3]Find the inverse of the matrix. Give exact values. Non-integers can be given as decimals or as simplified fractions.
Calculate Determinant: To find the inverse of a 2×2 matrix, we use the formula:Inverse(A)=(det(A)1)×adj(A)where det(A) is the determinant of matrix A and adj(A) is the adjugate of matrix A.First, we need to calculate the determinant of the given matrix.
Find Adjugate: The determinant of a 2×2 matrix [abcd] is calculated as ad−bc. For our matrix [5−36−3], the determinant is (5×−3)−(6×−3).
Calculate Inverse: Calculating the determinant:det(A)=(5×−3)−(6×−3)det(A)=−15−(−18)det(A)=−15+18det(A)=3The determinant of the matrix is 3.
Multiply by 1/3: Next, we need to find the adjugate of the matrix. The adjugate of a 2×2 matrix [abcd] is [d−b−ca]. For our matrix [5−36−3], the adjugate is [−33−65].
Simplify Fraction: Now we can find the inverse of the matrix by multiplying the adjugate by det(A)1.Inverse(A)=31×[−33−65]
Simplify Fraction: Now we can find the inverse of the matrix by multiplying the adjugate by 1/det(A). Inverse(A)=(1/3)×[−33−65] Multiplying the adjugate by 1/3: Inverse(A)=[(−3/3)(3/3)(−6/3)(5/3)]Inverse(A)=[−11−25/3]
Simplify Fraction: Now we can find the inverse of the matrix by multiplying the adjugate by 1/det(A). Inverse(A)=(1/3)×[−33−65] Multiplying the adjugate by 1/3: Inverse(A)=[(−3/3)(3/3)(−6/3)(5/3)]Inverse(A)=[−11−25/3] We can simplify the fraction 5/3 to its decimal equivalent if needed. 5/3 is approximately 1.6667. So the inverse matrix can also be written as: Inverse(A)=[−11−21.6667]