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AP EAMCET · Maths · Complex Number

If \(x=-5+2 \sqrt{-4}\), then the value of \(x^4+9 x^3+35 x^2-x+4\) is

  1. A \(80\)
  2. B \(160\)
  3. C \(-160\)
  4. D \(-80\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(-160\)

Step-by-step Solution

Detailed explanation

\(x=-5+2 \sqrt{-4}\) \(\begin{aligned} & x+5=4 i \\ & (x+5)^2=(4 i)^2 \\ & x^2+10 x+25=-16 \\ & x^2+10 x+41=0\end{aligned}\) Let \(x^4+9 x^3+35 x^2-x+4=\left(x^2+10 x+41\right)(p(x))+\mathrm{R}\)…