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secondary 4 | A Maths
5 Answers Below
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For part i) i got -2 and -8. Given solution k=-2. May I know why -8 is rejected? Thank you.
Date Posted: 8 months ago
Views: 105
-8 is acceptable too
no need to rej.
no need to rej.
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Actually -8 also possible but numbers are difficult to calculate
Idk why they reject
Part 1/2
Idk why they reject
Part 1/2
Date Posted:
8 months ago
Thank you so much for your prompt response.
So -8 is also the answer? Lol...
So -8 is also the answer? Lol...
Yeah
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There part 2/2
If you graph it -8 is also possible
If you graph it -8 is also possible
Date Posted:
8 months ago
K=-8 is rejected because when k=-8, y= x(x-8)^3. When k=-8, dy/dx is 0 when x=8 and not when x=2. Dy/dx=o when k=-2 when x=2. Hence, k=-2 and k=-8 is rejected.
Hope this helps.
Hope this helps.
My dy/dx is (x+k)^2.(4x+k).
When i sub in x=2, k=-2 and x=2, k=-8, both get 0
When i sub in x=2, k=-2 and x=2, k=-8, both get 0
Pls take a look at my working/explanation. Hope it helps. There is slightly more to do to determine the value of k in this question. For an intermediate question like this, more conditions could be placed in the question so that it is less challenging than it is supposed to be. Anyway, you have gotten the concepts of maxima and minima right, so no worries :)
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Hope this is clear.
Date Posted:
8 months ago
Thank you so much, will try to understand it.
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