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secondary 4 | A Maths
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Jung Wook Young
Jung Wook Young

secondary 4 chevron_right A Maths chevron_right Singapore

Need help for all ):

Date Posted: 8 months ago
Views: 88

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Erfana Beevee Binte Hassan Shariff
Erfana Beevee Binte Hassan Shariff's answer
275 answers (Tutor Details)
1st
For 4(a), use laws of natural log to split ln (a/b) into ln a - ln b, and then differentiate.

For (b), to show it is a decreasing function, dy/dx <0. -11 <0. So for dy/dx to be <0, thr denominator >0. So, (2+x)(3x-5) >0.
Hope this helps.
Jung Wook Young
Jung Wook Young
8 months ago
Thanks
Jung Wook Young
Jung Wook Young
8 months ago
Thank you
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Erfana Beevee Binte Hassan Shariff
Erfana Beevee Binte Hassan Shariff's answer
275 answers (Tutor Details)
Use product rule to differentiate y.
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Erfana Beevee Binte Hassan Shariff
Erfana Beevee Binte Hassan Shariff's answer
275 answers (Tutor Details)
Differentiate using rules of natural log.
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Erfana Beevee Binte Hassan Shariff
Erfana Beevee Binte Hassan Shariff's answer
275 answers (Tutor Details)
Use laws of natural log to split ln (a/b) into lna -lnb and then differentiate.
Recall gradient of 2 perpendicular lines, when multiplied = -1