The complex number z = i - 1 cos π 3 + i sin π 3 is equal to:

The complex number z=i-1cosπ3+isinπ3 is equal to:
  1. 2icos5π12-isin5π12
  2. cosπ12-isinπ12
  3. 2cosπ12+isinπ12
  4. 2cos5π12+isin5π12

Solution

Given,

z=i-1cosπ3+isinπ3

z=2-12+i2cosπ3+isinπ3

Now argument of complex number -12+i2 is 3π4

So, by euler's formula eiθ=cosθ+isinθ we get,

z=2ei3π/4eiπ/3

z=2ei5π/12

z=2cos5π12+isin5π12

Asked in: JEE Main 2023 (31 Jan Shift 2)

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