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Given two complex numbers, find by inspection the one that is a root of a given quartic real polynomial and hence find the other roots. 

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Consider both methods shown to get the correct answer to the question below.
After looking through both methods, choose which one you prefer and say why, giving a full explanation of your choice.

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Remember to compare efficiency, clarity of setting out, the reader's ability to follow the logic used easily in your answer.

Question

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Given  $\\displaystyle f(z) = \\simplify[std]{z ^ 4+ 4*z ^ 3+ 28 * z^2 +240z+800}$, one of the following complex numbers is a root $z_1$ of the equation $f(z)=0$.

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Choose the correct value for $z_1$:     (i)  $1-4i$      or     (ii)  $-4+2i$

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Please give your full reasoning for which of the methods shown above you prefer.

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You should aim to write about 50 words in your answer.

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Then send it to Shaheen Charlwood via Teams direct chat before the submission time given (usually the end time of the exam).

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