AP EAMCET202123 Aug 2021Morning ShiftMathematicsComplex NumberActual
( 8 +i 8 )^8 ( 8 -i 8 )^8 is equal to
Options
- Ai
- B-i
- C1
- D2
Correct answer
C. 1
Step-by-step solution
aligned & ( 8 +i 8 )^8 ( 8 -i 8 )^8 & = i^8 ( 8 -i 8 )^8 (-i)^8 ( 8 +i 8 )^8 & =+ ( 8 -i 8 )^8 ( 8 +i 8 )^8 & =+ (e^ -i / 8 )^8 (e^ i / 8 )^8 = & + e^ -i e^ i [ e^ i = +i ] & =+ -i +i & = +(-1) (-1) =+1 aligned