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1. ------

I multiplied out the top to give x^2 - 5x - 24 over x.

Now I'm confused because I differentiated it to give :
2x-5 over 1 , but the answer involves subtracting the top from bottom . Why does subtracting happen before the differentiation ?
2. You can cancel this down further to x - 5 - 24/x, which is a much easier way to differentiate.

This seems to be an AS question, it's not as simple when you have a quotient just to differentiate top and then bottom (explained at A2).
3. (Original post by WildBerry)

------

I multiplied out the top to give x^2 - 5x - 24 over x.

Now I'm confused because I differentiated it to give :
2x-5 over 1 , but the answer involves subtracting the top from bottom . Why does subtracting happen before the differentiation ?
Is this an AS question?
4. Yeah C1 question AS
5. (Original post by WildBerry)

------

I multiplied out the top to give x^2 - 5x - 24 over x.

Now I'm confused because I differentiated it to give :
2x-5 over 1 , but the answer involves subtracting the top from bottom . Why does subtracting happen before the differentiation ?

then

now do you understand?
6. (Original post by ilyking)

then

now do you understand?
Thanks alot , that made it seem much easier =)

Yeah , y= is when its all subtracted out , dy/dx is that differntiated
7. (Original post by WildBerry)
Thanks alot , that made it seem much easier =)

Yeah , y= is when its all subtracted out , dy/dx is that differntiated
subtracted isn't the right word. "Simplified" is.

Just make sure you know when you start the differentiation process (simplify first completely, then begin the differentiated).

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