NDA2020MathematicsDeterminantsActual
What is the value of the determinant | array ccc i & i^2 & i^3 i^4 & i^6 & i^8 i^9 & i¹² & i¹⁵ array | where i= -1 ?
Options
- A0
- B-2
- C4 i
- D-4 i
Correct answer
D. -4 i
Step-by-step solution
| array ccc i & i^2 & i^3 i^4 & i^6 & i^8 i^9 & i¹² & i¹⁵ array |= | array ccc i & -1 & -i 1 & -1 & 1 i & 1 & -i array | aligned & =i(i-1)-1(i-(-i))-i(1+i) & =i^2-i-2 i-i-i^2=-4 i aligned