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**[Solved]u=2+i.By considering the arg of u/u* or otherwise**

**Solved*## Homework Statement

u=2+i.

u*=2-i

"By considering the arg of u"/u* or otherwise prove that tan^-1(4/3)=2tan^-1(0.5).That's the question,explain how do pls?

## Homework Equations

arg(u/u*)=arg u -arg u*

tan A=opposite side/adjacent side

tan2A=2tanA/(1-tan^2 A)

## The Attempt at a Solution

tanA=1/2

2tanA=1

tan2A(1-tan^2 A)=1

*Stuck here,guide pls?

Edit*

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