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Question: Answered & Verified by Expert
Let $\mathrm{f}(\mathrm{x})=[|\mathrm{x}|-\mid \mathrm{x}-1]]^{2}$
What is $\mathrm{f}^{\prime}(\mathrm{x})$ equal to when $0 < \mathrm{x} < 1 ?$
MathematicsApplication of DerivativesNDANDA 2016 (Phase 2)
Options:
  • A 0
  • B $2 x-1$
  • C $4 x-2$
  • D $8 x-4$
Solution:
1597 Upvotes Verified Answer
The correct answer is: $8 x-4$
Given $f(x)=(|x|-|x+1|)^{2}$
$f(x)=\left\{\begin{array}{cc}1 & x \leq 0 \\ (2 x-1)^{2} & 0 < x < 1 \\ 1 & x \geq 1\end{array}\right.$
When $0 < x < 1$
$f(x)=(2 x-1)^{2}$
$f^{\prime}(x)=2(2 x-1) \cdot 2=4(2 x-1)$
$f^{\prime}(x)=8 x-4$

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