[Bawse]

Hi, so far I've working my way through Binomial Expansion, but question 1G excercise 3B in the Edexcel C4 book has got me stuck.

The question is - 'Find the the binomial expansions of the following in ascending powers of x as far at the term in x^3. Then state the range of values of x for which the expansions are valid.

1G)

(1+x)/(2+x)

So far I have put it in the form (1+x)(2+x)^-1 but then am unsure as what to do next?

[ewellbelove]

(Original post by Bawse)
Hi, so far I've working my way through Binomial Expansion, but question 1G excercise 3B in the Edexcel C4 book has got me stuck.

The question is - 'Find the the binomial expansions of the following in ascending powers of x as far at the term in x^3. Then state the range of values of x for which the expansions are valid.

1G)

(1+x)/(2+x)

So far I have put it in the form (1+x)(2+x)^-1 but then am unsure as what to do next?

Use the expansion for each bracket allowing (n) to be the power, also do not forget that the number in front of the x value has to be one so take a factor of 2 out not forgeting you are actually taking 2^-1 out. Unsure about the range as i cannot remember my self hope this helps

[aznkid66]

Since it's a rational function, the range of x (domain) should be when the denominator ≠ 0.

[Bawse]

Thanks guys, can't believe it was as simple as realising that the power to the bracket was and I had to multiply the binomials together, cheers!