Let S = z = x + i y : z - 1 + i ≥ z , z < 2 , z + i = z - 1 . Then the set of all values of x ,…

Let S=z=x+iy:z-1+iz,z<2,z+i=z-1.  Then the set of all values of x, for which w=2x+iyS for some y, is
  1. -2,122
  2. -12,14
  3. -2,12
  4. -12,122

Solution

Given,

z-1+iz, z<2 & z+i=z-1

Now solving z-1+iz put z=x+iy we get, x-y1 so plotting we get,

Now solving z<2 we get, x2+y2<4 on plotting the diagram we get,

Now solving z+i=z-1 we get x+y=0

Now combine diagram of x+y=0 & x-y1 will be,

Now combining all diagram we get,

Hence

w=2x+iyS

Now for wS2x12 so x14

Now 2x+y=0y=-2x putting the value in x2+y2<4

2x2+2x2<4

x2<12x-12,12

So, x-12,14

Asked in: JEE Main 2022 (29 Jul Shift 2)

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