I did some questions from some trial papers and realised that
some of my answers do not tally with the answer sheet. I have
checked it numerous times and seem not to be able to spot any
errors. Please take a look as I might have overlooked them.
Firstly, the binomial question.
Find the 1st 3 terms of the expansion, in ascending powers of x
of (2x - 3)^5 and (1-3x)^5
I got -243 + 810x - 1080x^2 +... and 1 - 15x + 90x^2 +...
respectively.
Next comes the part I did wrong.Hence, find the coefficient of
x^2 in the expansion of (-6x^2 + 11x - 3)^5
The answer says it should be -13473 however I got a value LARGER
than that... should you multiply (-243 + 810x -
1080x^2+...)(1-15x+90x^2+...)?
Second question.
given that the expression 2x^2 - 6x +5 leaves the same remainder
when divided by x-p or x-q, where p is not equal to q, show that
p+q = 3. Hence find the remainder when expression is divided by 2x
- p -q.
I got 0.5 as the remainder but answer says it is -8.5. I'm
pretty sure I got this answer correct cuz I checked it against the
answer fro long division method. They tally.
Lastly, thanks all.