Q34. (cos20+isin20)5 ÷ (cos 30+ isin30)3=?

Correct answer: C. cos 10 + i sin 10

  • A. cos 20+ i sin 20
  • B. cos 30 + i sin30
  • C. cos 10 + i sin 10
  • D. cos20 - i sin 20

Explanation

Answer: b (x=1, y=0)Solution: [1-1+ii]100= 1-i1 +i ×1-i1-i100= 1-i(1-i)(1+i)(1-i)100=(1-i)212- i2100=12 -21i+ i212 - i2 100=1-2i+(-1)1-(-1)100 =1-2i-11+1100= -2i 2100= -i100=-i250=-(-1)50= 1 In x+iy form 1+0i

Last updated

Related questions