-Perform the following operation and write the result in standard form (a+bi). 1/(2+i)^4 -Also, is synthetic division the only way you can factor f(x)=2x^3+3x^2-20x-21? Thank you!!
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This ia a start of the first one. $\displaystyle \frac{1} {{\left( {2 + i} \right)^4 }} = \frac{{\left( {2 - i} \right)^4 }} {{5^4 }}$
thanks but how did you get 5^4?
Originally Posted by ss103 thanks but how did you get 5^4? $\displaystyle \frac{1}{{z^4 }} = \left( {\frac{{\overline z }} {{\left| z \right|^2 }}} \right)^4 \quad ,\quad \left| {2 + i} \right|^2 = 5 $
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