Using elementary transformations, find the inverse of matrix [31027], if it exists.
Open in App
Solution
Let A=[31027]
We know that A=IA ⇒[31027]=[1001]A
Applying R1→R1−R2 ⇒[3−210−727]=[1−00−101]A ⇒[1327]=[1−101]A
Applying R2→R2−2R1 ⇒[132−2(1)7−2(3)]=[1−10−2(1)1−2(−1)]A ⇒[1301]=[1−1−23]A
Applying R1→R1−3R2 ⇒[1−3(0)3−3(1)01]=[1−3(−2)−1−3(3)−23]A ⇒[1001]=[7−10−23]A ⇒I=[7−10−23]A
This is similar to I=A−1A
Thus, A−1=[7−10−23]