2013 THREE(b)

Achievement
Question
For the function f(x)=x+16x2f(x)=x+\dfrac{16}{x-2}, find the xx-values of any stationary points.

*You must use calculus and clearly show your working, including any derivatives you need to find when solving this problem.*
Official Answer
f(x)=116(x2)2f'(x)=1-16(x-2)^{-2}

Turning point when f(x)=0f'(x)=0

1=16(x2)21=\dfrac{16}{(x-2)^2}

(x2)2=16(x-2)^2=16

x=2x=-2 or x=6x=6
Grading Criteria

Achievement (u)

  • Correct solution with correct derivative.

Merit (r)

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Excellence T1

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Excellence T2

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