Q99 / 180 · COMEDK 2021 · MathematicsQ24 / 53 · COMEDK 2021 · Mathematics · Complex Number · Power of iotaPractise ModeOffEvaluate [i18+(i1)25]3.Correct answerA2(1−i)B7(i−1)C2−7iD8i+4Solutioni18=i16⋅i2=1⋅(−1)=−1i1=i2i=−1i=−i⇒(i1)25=(−i)25=(−1)25⋅i25=−1⋅i24⋅i=−i[i18+(i1)25]3=[−1+(−i)]3=[−(1+i)]3=−(1+i)3(1+i)2=1+2i+i2=2i(1+i)3=2i(1+i)=2i+2i2=2i−2=−2+2i−(1+i)3=−(−2+2i)=2−2i=2(1−i)Correct option: (1)Hence, the correct answer is option: 'A'.PreviousNext