Q212 · Practice questionTechnology-freeComplex familiar5 marks
QUESTION 212 (5 marks)
Let .
a)[2 marks]
Find all stationary -values.
b)[2 marks]
Classify the stationary points.
c)[1 mark]
Find the coordinates of the local maximum.
WORKED SOLUTION
5 marksPractice marking scheme
ANSWER
, so local maximum is .
Worked solution
Part (a): , so .
Part (b): changes + to - at (local maximum) and - to + at (local minimum). Equivalently, the second derivative is negative at and positive at .
Part (c): , so local maximum is .
Part (a): completes the requested reasoning and obtains a correct result.
Part (b): completes the requested reasoning and obtains a correct result.
Part (c): completes the requested reasoning and obtains a correct result.
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