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# C1 Differentiation Tweet

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1. C1 Differentiation
I'm stuck on the question which is below:

If , show that

Below is my working out:

This differentiates to provide:

I multiply the above by 2x to get:

What have I done wrong?????

Thanks for any help provided.
2. Re: C1 Differentiation
(Original post by krisshP)
I'm stuck on the question which is below:

If , show that

Below is my working out:

This differentiates to provide:

I multiply the above by 2x to get:

What have I done wrong?????

Thanks for any help provided.
dy/dx = 1/[2(x)^(1/2)]

2x*dy/dx = 2x/2x^(1/2)

laws of indices......x^1 - x^(1/2)

2's cancel out and you know y = x^1/2
3. Re: C1 Differentiation
(Original post by boromir9111)
dy/dx = 1/[2(x)^(1/2)]

2x*dy/dx = 2x/2x^(1/2)

laws of indices......x^1 - x^(1/2)

2's cancel out and you know y = x^1/2
How do you get the following:

dy/dx = 1/[2(x)^(1/2)]

I do not understand.
btw can you please use latex.

Thanks
4. Re: C1 Differentiation
(Original post by krisshP)
How do you get the following:

dy/dx = 1/[2(x)^(1/2)]

I do not understand.
btw can you please use latex.

Thanks
No worries

Your method of calculating dy/dx is correct but it's better to leave it in fraction form as it's more neater!
Last edited by boromir9111; 29-07-2012 at 15:51.
5. Re: C1 Differentiation
(Original post by krisshP)
I'm stuck on the question which is below:

If , show that

Below is my working out:

This differentiates to provide:

I multiply the above by 2x to get:

What have I done wrong?????

Thanks for any help provided.
Hint:

Edit: woops I'm a bit late!
Last edited by Lord of the Flies; 29-07-2012 at 15:52.
6. Re: C1 Differentiation

What have I now done wrong???????

btw thanks for the tip on latex.
7. Re: C1 Differentiation
(Original post by krisshP)

What have I now done wrong???????

btw thanks for the tip on latex.

It should be
8. Re: C1 Differentiation
(Original post by krisshP)

What have I now done wrong???????

btw thanks for the tip on latex.
If you insist on doing it this way then you should be careful when applying laws of indices here

x^1*x^(-1/2) does not give x^2
9. Re: C1 Differentiation
(Original post by krisshP)

What have I now done wrong???????

btw thanks for the tip on latex.

You are not using the rules of indices correctly

10. Re: C1 Differentiation
Then

Then
11. Re: C1 Differentiation
(Original post by TenOfThem)
Then

Then
Thanks a lot for your support.

I understand now.
12. Re: C1 Differentiation
(Original post by krisshP)
Thanks a lot for your support.

I understand now.
ok good