How Can You Simplify the Inequality |Im(z^2 - z̅ + 6)| < 12 Given |z| < 3?

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Homework Statement



Know: modulus(z) < 3
WTS: |Im(z2 - zbar + 6)| <12

where zbar is the complex conjugate

Homework Equations



z = x + iy

The Attempt at a Solution



|Im(z2 - zbar + 6)|
= |Im(x2 + 2i*x*y - y2 - x + iy + 6)|
= |2xy + y|

So I want to show |2xy + y|< 12

I already proved it using maximization and Lagrange multipliers, but it seems like overkill, and I think there is some kind of arithmetic trick I am missing. Anyone see it?

Thanks
 
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|Im(z)|[tex]\leq[/tex] |z|
Then use the triangle inequality to derive an upper bound.
 
One thing to be careful about is to use:
[tex] |z_{1}-z_{2}|\leqslant ||z_{1}|-|z_{2}||[/tex]