# Is this a typo? - Integral of fraction

Part (1) of this question posted in post 3. Is it a type-o or correct. Not looking for solution.

Last edited:

Doug Huffman
Gold Member
Yes, it appears to be so, from what I can see.

Forgot the image

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.

Hint for part i): Try to rearrange ##6x^2-5x+3## into some polynome your can divide by ##12x-5## plus a constant.

Ya I differentiated the top and you get 12x-5 all over 12x-5.

Ah I see. Could be a typo. But this integral should be solvable as well.

Part 1&2 only worth 4% on exam paper. Seem like a but of work for 2%

Part 1&2 only worth 4% on exam paper. Seem like a but of work for 2%

Private theories are not allowed in this forum. :D But don't worry here. Sorry, I can only look at the math.

Mark44
Mentor
Anthonyk, why would you think the problem has a typo? This is an easy integral - just divide the numerator by the denominator.

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.

Anthonyk, why would you think the problem has a typo? This is an easy integral - just divide the numerator by the denominator.

That's are far as I got I had x-1.

Ya silly mistake by me.

Wondering the the solution the this question is right or wrong ?
Thanks

mfb
Mentor
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.

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.

mfb
Mentor
Looks right so far.

Mark44
Mentor
@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.

Ill finish later. Too many kids around[emoji86]

Thanks for the reminder mark44. Long time since i was in grade school as you call it

Latest attempt. Wondered if I'm right.

mfb
Mentor
Integrating x/2 gave x2/2?
And check what you have in the denominators and logs - but I guess those are just typos.

Should be X2/4