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# help with a question please, cheers ;) watch

1. OK in a random c3 maths thread i saw on the homepage there was the question someone posted to differentiate

this is what I did, but I'd like someone a bit more qualified to tell me if it's right or not

Derivative of
therefore if we can find the derivative of , we can do the rest pretty easily.
So, is a bit tricky, but as far as I can see,
therefore we can differentiate using the rule above and the product rule:

Therefore;

I think

:P
2. Almost.

has disappeared in the final equation.

This all assumes that y depends on x and is not just a constant (and you're differentiating wrt x).
3. (Original post by notnek)
Almost.

has disappeared in the final equation.

This all assumes that y depends on x and is not just a constant (and you're differentiating wrt x).
is that right then? (the edit)
and yer I know it's assuming that, but that;'s the whole point - it's boring otherwise.
4. i got 7Y^y-1xe^x^y
5. (Original post by victor_b1992)
i got 7Y^y-1xe^x^y
how did you work it out...cos that's different to mine, but unless you post your workings we can't really compare :P
6. THe original post is now correct.
7. (Original post by Toneh)
how did you work it out...cos that's different to mine, but unless you post your workings we can't really compare :P
i use the chain rule iam pretty show this is correct.

as differentiation of x^y= yx^y-1
8. (Original post by victor_b1992)
i use the chain rule iam pretty show this is correct.

as differentiation of x^y= yx^y-1
well yes that works if y is a constant, but i was differentiating it where y was a variable, so that doesn't work.
9. (Original post by Toneh)
well yes that works if y is a constant, but i was differentiating it where y was a variable, so that doesn't work.
so what did you get
10. (Original post by victor_b1992)
so what did you get
it's in the OP...
11. ok i see what you did kl sorry my head is just not screwed on property today.

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