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# c4 binomial expansion

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1. hi

Can someone help me understand where I went wrong on part b please, the answer is meant to be 19.22 instead of 1.922 but I don't know why I need to times by 10 here?

All my working out seems to be logical from as far as I can see

Thanks

Zacken?
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2. (Original post by Katiee224)
hi

Can someone help me understand where I went wrong on part b please, the answer is meant to be 19.22 instead of 1.922 but I don't know why I need to times by 10 here?

All my working out seems to be logical from as far as I can see

Thanks

Zacken?
No, when you plug in x=0.1, your approximation is for 7.1^(1/3). Not for 10 * (7.1)^(1/3).

(7100)^(1/3) is given by multiplying your approximation for 7.1^(1/3) by 10.

Remember that 8 - 9(0.1) = 7.1, not 7100.
3. (Original post by Zacken)
No, when you plug in x=0.1, your approximation is for 7.1^(1/3). Not for 10 * (7.1)^(1/3).

(7100)^(1/3) is given by multiplying your approximation for 7.1^(1/3) by 10.

Remember that 8 - 9(0.1) = 7.1, not 7100.
ohhhh I get it now thanks hehe

remind me to buy you a pint when you move to Cambridge

edit: when I turn 18
4. (Original post by Katiee224)
ohhhh I get it now thanks hehe

remind me to buy you a pint when you move to Cambridge

edit: when I turn 18
I think you mean Warwick.

I'm almost 18.
5. (Original post by Zacken)
I think you mean Warwick.

I'm almost 18.
I thought you firmed Cambridge, my bad

Well I live near Warrick and I'd happily buy you a pint to say thanks
6. (Original post by Katiee224)
I thought you firmed Cambridge, my bad

Well I live near Warrick and I'd happily buy you a pint to say thanks
I did, but I'm pretty sure I've missed my offer.

Sounds fab. That'll be one "pro" for missing my offer and having to go to Warwick.

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