COMEDK2023MathematicsComplex Number
If i= -1 and n is a positive integer, then i^n+i^ n+1 +i^ n+2 +i^ n+3 is equal to
Options
- A1
- Bi
- Ci^n
- D0
Correct answer
D. 0
Step-by-step solution
aligned Given, i^n+ & i^ n+1 +i^ n+2 +i^ n+3 =i^n (1+i+i^2+i^3 ) & =i^n (1+i+(-1)+ (i^2 ) i ) & =i^n(1+i+(-1)+(-1) i) & =i^n[(1+i)-(1+i)]=i^n(0)=0 aligned