griff's answer to choot's Secondary 4 A Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
griff
Griff's answer
71 answers (Tutor Details)
1st
Idk if i have any careless but seems like the qn is flawed. Looking at equation 1 and 5 they arent logical
choot
Choot
7 months ago
hm.. tyty
Eric Nicholas K
Eric Nicholas K
7 months ago
Try putting as A/(x - 1) + B/(x + 1) + C/(x + 1)^2 or perhaps try a different set of values for x

A = 0.25, B = -0.25, C = 0.5 based on my format
Eric Nicholas K
Eric Nicholas K
7 months ago
1 = (Ax + B) (x + 1) + C (x^2 - 1)

I will attempt to compare coefficients instead

1 = Ax^2 + Ax + Bx + B + Cx^2 - C
1 = (A + C)x^2 + (A + B)x + (B - C)

Then
A + C = 0 ==> C = -A
A + B = 0 ==> B = -A
B - C = 1

Seems false to me either.

I suspect that it’s the format that is the issue because we can technically factorise the denominator further.