KCET2013MathematicsDeterminants
If A= [ array cc & 2 2 & array ] and |A³ |=125 , then is equal to
Options
- A1
- B2
- C3
- D5
Correct answer
C. 3
Step-by-step solution
Given, A= [ array ll & 2 2 & array ] Now, |A|= | array cc & 2 2 & array |= ²-4...(i) Also, given, array ll & |A³ |=125 & |A|³=125=(5)³ ( |A^ n |=|A|^ n ) & |A|=5 array On putting this value in Eq. (i), we get aligned 5 &= ²-4 ² &=9=(3)² &= 3 aligned