## Can anyone help on this question

PSLE marks the graduation of Primary school students and their entry into Secondary schools as teenagers. Discuss all issues about Secondary schooling here.

### Can anyone help on this question

Hi

Anyone can help in this question?

Thanks1

bluesky63
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### Re: Can anyone help on this question

1. Find out the relationship of the figure. The distance between the boy and the heli is the hypotenuse. For right angled triangle, the 3 sides are related by sum of squares of the two short sides --> …….. theorem

2. Given one side is changing at 25m/s , make this side x, and rate of change of x, dx/dt =25 m/s

3. Given another side is constant, so the 3rd side is…. y= f(x)=theorem from step 1. find dy/dx

4. Using chain differentiation, rate of change of y, dy/dt= dy/dx. dx/dt

5. post back if you still need more clues.

bluesclue
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### Re: Can anyone help on this question

Hi,

Can explain more on how to form the y = f(x)? Thanks !

bluesky63
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### Re: Can anyone help on this question

bluesclue
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### Re: Can anyone help on this question

Hi bluesclue,

what is the x value to sub in dy/dx ? thanks

bluesky63
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### Re: Can anyone help on this question

bluesky63 wrote:Hi bluesclue,

what is the x value to sub in dy/dx ? thanks

X is the horizontal distance so x = 72 add required by question

pinkapple
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### Re: Can anyone help on this question

pinkapple wrote:
bluesky63 wrote:Hi bluesclue,

what is the x value to sub in dy/dx ? thanks

X is the horizontal distance so x = 72 add required by question

Thanks a lot... Got it !

bluesky63
YellowBelt

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