Complex Numbers 2 Question 17

17. The complex numbers sinx+icos2x and cosxisin2x are conjugate to each other, for

(a) x=nπ

(b) x=0

(c) x=(n+1/2)π

(d) no value of x

(1988, 2M)

Show Answer

Answer:

Correct Answer: 17. (a, c, d)

Solution:

  1. Since, (sinx+icos2x)=cosxisin2x

sinxicos2x=cosxisin2x

sinx=cosx and cos2x=sin2x

tanx=1 and tan2x=1

x=π/4 and x=π/8 which is not possible at same time.

Hence, no solution exists.



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक