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# C4, differentiation; watch

1. Could someone explain to me how the dy/dx was worked out in this question please?

This is what I got, I don't quite understand where the dy/dx in the equation comes from.

Thank you.
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2. (Original post by Y_123456)
Could someone explain to me how the dy/dx was worked out in this question please?

This is what I got, I don't quite understand where the dy/dx in the equation comes from.

Thank you.
Whenever you differentiate a 'y' term you have to put dy/dx next to it

For example, if you have
y = 5x+2

you differentiate both sides and get:

(1)dy/dx = 5
so dy/dx = 5
3. This is an example of IMPLICIT differentiation. in most cases you do differentiation where its something=y but in this case you cant seperate it so that something=y so you have to differentiate a different way. you use the same methods, but when differentiating a term with y in it you multiply by dy/dx. Surely youve been taught this? or are you trying to skip ahead before your class has gone over it?
4. You're using both the product rule and chain rule because your differentiating with respect to x

Edit: sorry if I sound a bit unclear, it's just that I've only just done this topic myself

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5. (Original post by GPODT)
Whenever you differentiate a 'y' term you have to put dy/dx next to it

For example, if you have
y = 5x+2

you differentiate both sides and get:

(1)dy/dx = 5
so dy/dx = 5
Thank you so much! I understand it now.
6. (Original post by J1994D)
This is an example of IMPLICIT differentiation. in most cases you do differentiation where its something=y but in this case you cant seperate it so that something=y so you have to differentiate a different way. you use the same methods, but when differentiating a term with y in it you multiply by dy/dx. Surely youve been taught this? or are you trying to skip ahead before your class has gone over it?
Looking through the chapter before being taught. Not doing a good job am I. And thank you for explaining.
7. (Original post by SDavis123)
You're using both the product rule and chain rule because your differentiating with respect to x

Edit: sorry if I sound a bit unclear, it's just that I've only just done this topic myself

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No worries. Thank you, every little helps.

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