- #1
- 125
- 0
Part (1) of this question posted in post 3. Is it a type-o or correct. Not looking for solution.
Last edited:
Is this a typo? - Integral of fraction
X).Insummary, Anthonyk thinks that the problem has a typo because it is an easy integral and he differentiated the top to get 12x-5 all over 12x-5.f
- #2
Doug Huffman
Gold Member
- 808
- 111
Yes, it appears to be so, from what I can see.
- #3
- 125
- 0
- #4
- 125
- 0
Forgot the image
- #5
- 94
- 10
What is a type-o? Or do you think it is a typo? Then type-o probably is a typo.
The integrals look ok so far.
The integrals look ok so far.
- #6
- 94
- 10
Hint for part i): Try to rearrange ##6x^2-5x+3## into some polynome your can divide by ##12x-5## plus a constant.
- #7
- 125
- 0
Ya I differentiated the top and you get 12x-5 all over 12x-5.
- #8
- 94
- 10
Ah I see. Could be a typo. But this integral should be solvable as well.
- #9
- 125
- 0
Part 1&2 only worth 4% on exam paper. Seem like a but of work for 2%
- #10
- 94
- 10
Private theories are not allowed in this forum. :D But don't worry here. Sorry, I can only look at the math.
- #11
Mark44
Mentor
- 37,231
- 9,393
Anthonyk, why would you think the problem has a typo? This is an easy integral - just divide the numerator by the denominator.
- #12
- 125
- 0
Lecturer thinks it is because of the low mark. Looking back a previous exam papers made an assumption. If We are wrong I hold my hand up.
- #13
- 125
- 0
That's are far as I got I had x-1.
- #14
Mark44
Mentor
- 37,231
- 9,393
Well, that's wrong. The first term in the quotient should by (1/2)x. See http://en.wikipedia.org/wiki/Polynomial_long_division.
Last edited:
- #15
- 125
- 0
Ya silly mistake by me.
- #16
- 125
- 0
Wondering the the solution the this question is right or wrong ?
Thanks
- #17
mfb
Mentor
- 36,483
- 13,591
What happened in (4)? The denominators vanished?
Also, what happens if you differentiate your result? Do you get the initial fraction? This is often a very easy check you can always do if you are unsure.
The whole substitution is not helpful here. Posts 6 and 11 show the best approach.
Also, what happens if you differentiate your result? Do you get the initial fraction? This is often a very easy check you can always do if you are unsure.
The whole substitution is not helpful here. Posts 6 and 11 show the best approach.
- #18
- 125
- 0
This solution is from class. We were given a reason why that were moved but I can remember.
When studying on my own I divided the polynomial but the devision didn't look right. I'll attempt it again and post later. Thanks.
When studying on my own I divided the polynomial but the devision didn't look right. I'll attempt it again and post later. Thanks.
- #19
- 125
- 0
- #20
mfb
Mentor
- 36,483
- 13,591
Looks right so far.
- #21
Mark44
Mentor
- 37,231
- 9,393
@anthonyk2013, once you've made it past grade school arithmetic, it's not a good idea to write fractions as mixed numbers (such as you have in your work). Instead of ##1 \frac 1 {24}## or ##1 \frac {23} {24}##, you really should write these as improper fractions, 25/24 and 47/24. Mixed numbers such as the ones you wrote are much harder to work with and can easily be confused if not written very carefully.
- #22
- 125
- 0
Ill finish later. Too many kids around[emoji86]
- #23
- 125
- 0
Thanks for the reminder mark44. Long time since i was in grade school as you call it
- #24
- 125
- 0
Latest attempt. Wondered if I'm right.
- #25
mfb
Mentor
- 36,483
- 13,591
Integrating x/2 gave x2/2?
And check what you have in the denominators and logs - but I guess those are just typos.
And check what you have in the denominators and logs - but I guess those are just typos.
- #26
- 125
- 0
Should be X2/4