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# Core Maths 3: Differentiation using the quotient rule

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1. Hi there

Please could someone tell me if the below is correct;

Many thanks
Jackie
2. I haven't checked the algebra but how did you go from the fraction at the bottom left to the next stage ? The question doesn't give us x.
3. (Original post by jackie11)
Hi there

Please could someone tell me if the below is correct;

Many thanks
Jackie
According to the question you should leave your answer as

Why did you wrote
4. (Original post by raheem94)
According to the question you should leave your answer as

Why did you sub in x=1?
He didn't sub in x=1 otherwise the top would be 1 + 2 - 1 = 2

He could make into a proper fraction I guess.
5. (Original post by member910132)
He didn't sub in x=1 otherwise the top would be 1 + 2 - 1 = 2

He could make into a proper fraction I guess.
Thanks for correcting me, do you understand what he was trying to do?

This can easily be made into a proper fraction, but i don't think he was trying to do this.
6. (Original post by raheem94)
According to the question you should leave your answer as

Why did you sub in x=1?
ok thankyou, no I just assumed that when you have the same thing on the top and bottom, i.e.

10/10, it becomes 1/1

So that's what I did for x^2/x^2 and 2x/2x
7. (Original post by jackie11)
Hi there

Please could someone tell me if the below is correct;

Many thanks
Jackie
Jackie, Jackie, Jackie

You CANNOT do that

You CANNOT cancel the x^2 and then cancel the 2x's ... NO NO NO NO
8. (Original post by jackie11)
ok thankyou, no I just assumed that when you have the same thing on the top and bottom, i.e.

10/10, it becomes 1/1

So that's what I did for x^2/x^2 and 2x/2x
10/10 becomes 1/1 but here the top has -1 and the bottom has +1.

If you want to simplify it, then you can do it in the following way,
9. (Original post by jackie11)
ok thankyou, no I just assumed that when you have the same thing on the top and bottom, i.e.

10/10, it becomes 1/1

So that's what I did for x^2/x^2 and 2x/2x
No you can't do that. say if we have , that ISN'T equal to

You can only simplify a fraction if the top and bottom are multiplied by the same factor, not 'added on' by the same amount.

E.g. the above isn't allowed, but this is:

EDIT: I'm sure you probably do know this, and are just getting confused but hopefully the examples helped
10. aww thank you all so much

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