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# product rule or chain rule how do you decide? watch

1. Hi please some one help me with the attached differentiation problem?

I get a bit confused in recognizing if it is a chain rule or product rule

I am aware if it is a chain rule then it has to be a function of a function

Thanks Zamzam
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2. Combination diferentiation 13-3-16.pdf (282.5 KB, 85 views)
3. (Original post by zamzam)
Hi please some one help me with the attached differentiation problem?

I get a bit confused in recognizing if it is a chain rule or product rule

I am aware if it is a chain rule then it has to be a function of a function

Thanks Zamzam
definitely a product rule
each term has a mini chain which most people can do on the spot.
4. If it is a product of two functions, say you would use the product rule.
If it is a function of a function, say , you would use chain rule.
5. Product rule is when its a function times a function. Chain is when there is a function in a function that you can't do normally.

This would be a product rule, as e^(x/2) x sin(3x)

Is effectively that function, as you can see it is two functions multiplied by each other to form a product.
6. (Original post by Dinasaurus)
Product rule is when its a function times a function. Chain is when there is a function in a function that you can't do normally.

This would be a product rule, as e^(x/2) x sin(3x)

Is effectively that function, as you can see it is two functions multiplied by each other to form a product.
Surely it's chain rule to differentiate e^(x/2), chain rule to differentiate sin(3x) and then use those values in the product rule. Or am I missing something?
7. (Original post by RayApparently)
Surely it's chain rule to differentiate e^(x/2), chain rule to differentiate sin(3x) and then use those values in the product rule. Or am I missing something?
I think most of the time, those are seen as standard differentials. Like you can use chain rule but I think most people know what it is without the method?
8. (Original post by Dinasaurus)
I think most of the time, those are seen as standard differentials. Like you can use chain rule but I think most people know what it is without the method?
Oh yeah I guess so lol
9. sadly I have been expelled ....

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