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If | eeze^{e^z}eez | = 1 for a complex number z = x + iy, x, y ∈ R,then.which of thefollowing is true ?
Question

If | eeze^{e^z} | = 1 for a complex number z = x + iy, x, y ∈ R,then.

which of thefollowing is true ?

A.

x=nπx=n\pi for some integer n .​

B.

y=(2n+1)π2y=(2n+1)\frac{\pi}{2} for some integer n .​​

C.

y=nπy=n\pi for some integer n .​

D.

x=(2n+1)π2x=(2n+1)\frac{\pi}{2} for some integer n.​

Correct option is B

The given condition is eez=1, where z=x+iy.Step 1: Expand eezWe can write:eez=eex+iy=eexeiy.=eexcosy+exisiny=eexcosyeexisinyThe modulus of eez is:eez=eexcosyeexisiny=eexcosyeexisinyTo satisfy the given condition:eez=eexcosyeexisiny=1As, eiθ=1,eexcosy=1 is required. cosy=0 y=(2n+1)π2Hence, Option B is correct.\text{The given condition is } \left| e^{e^z} \right| = 1, \text{ where } z = x + iy. \\[10pt]\textbf{Step 1: Expand } e^{e^z} \\[10pt]\text{We can write:} \\[10pt]e^{e^z} = e^{e^{x+iy}} = e^{e^x e^{iy}}. \\[10pt]=e^{e^x \cos y + e^x i \sin y} = e^{e^x \cos y} \cdot e^{e^x i \sin y} \\[10pt]\text{The modulus of } e^{e^z} \text{ is:} \\[10pt]\left| e^{e^z} \right| = \left| e^{e^x \cos y} \cdot e^{e^x i \sin y} \right| = \\[10pt]\left| e^{e^x \cos y} \right| \cdot \left| e^{e^x i \sin y} \right| \\[10pt]\text{To satisfy the given condition:} \\[10pt]\left| e^{e^z} \right| = \left| e^{e^x \cos y} \cdot e^{e^x i \sin y} \right| = 1 \\[10pt]\text{As, } | e^{i\theta} | = 1, \\[10pt]\left| e^{e^x \cos y} \right| = 1 \ \textit{is required.} \\[10pt]\implies \cos y = 0 \implies y = \frac{(2n+1)\pi}{2} \\[10pt]\text{Hence, } \textbf{Option B} \text{ is correct.}​​

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