C4 Binomial ExpansionWatch

Thread starter 7 years ago
#1
Write up to x^3

(x^2+3)/ cubed root(8-x)^2

I rewrote as (X^2 +2) x ((8 - x)^2)^-1/3)

Then I tried to rewrite the second part in a (1-u) way. But wasn't sure what to take out as a factor. Because 8^2^-1/3 is 1/4. Or whether to expand the bracket in the cube root.

I really appreciate any help anyone can offer
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quote
7 years ago
#2
(Original post by fortunecookie)
Write up to x^3

(x^2+3)/ cubed root(8-x)^2

I rewrote as (X^2 +2) x ((8 - x)^2)^-1/3)

Then I tried to rewrite the second part in a (1-u) way.
Good thinking.

But wasn't sure what to take out as a factor. Because 8^2^-1/3 is 1/4. Or whether to expand the bracket in the cube root.

I really appreciate any help anyone can offer
Re-writing it, you have:

(X^2 +2) x ((8 - x))^-2/3)

So, as you first thought you want to get rid of that 8, giving:

(X^2 +2) x (1/4) ((1 - x/8))^-2/3)

And go from there.
quote
7 years ago
#3
(Original post by fortunecookie)
Write up to x^3

(x^2+3)/ cubed root(8-x)^2

I rewrote as (X^2 +2) x ((8 - x)^2)^-1/3)

Then I tried to rewrite the second part in a (1-u) way. But wasn't sure what to take out as a factor. Because 8^2^-1/3 is 1/4. Or whether to expand the bracket in the cube root.

I really appreciate any help anyone can offer
You are on the right way
Taking out 8 as factor from the second part
1/4 x (1-x/8)^(-2/3)
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