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1. hey guys,
just cam back from uni. had a test which is like 15% of my cw. pretty confident but just some question that if you can confirm i got right that'll be great.

1) integration by substitution between x=o (lower limit) and x=1 (upper limit). Did anyone get 6?

2) can;t remember exactly by if you have something like , to find dy/dx will you just use the quotient rule to find the first part and then "+ 2"?

thanks
2. I could be wrong, but I think:

1) Answer = (8/3)*2^(3/2). After integrating, I got (8/3)(x^2+1)^(3/2) -- what did you have?

2) You could use the quotient rule, but it would be a bit pointless. Just differentiate the numerator, then divide it by 2.
3. (Original post by Prokaryotic_crap)
hey guys,
just cam back from uni. had a test which is like 15% of my cw. pretty confident but just some question that if you can confirm i got right that'll be great.

1) integration by substitution between x=o (lower limit) and x=1 (upper limit). Did anyone get 6?

2) can;t remember exactly by if you have something like , to find dy/dx will you just use the quotient rule to find the first part and then "+ 2"?

thanks
I'm afraid your first answer is wrong. There is a surd in the answer.

There is no need to use the quotient rule on the second question (although you should have got the correct answer even if you did).

4. Oops garbage, damn internet lol. Ignore this post please
5. I got the answer as (16*sqrt(2))/3 - 8/3 for the first one

6. Unparseable or potentially dangerous latex formula. Error 4: no dvi output from LaTeX. It is likely that your formula contains syntax errors or worse.
8(u -1)^\frac{1}{2} u^\frac{1}{2} \frac{du}{2(u-1)^\frac{1}{2}
simplyfying that and subbung u=2 and u=1 and then taking the latter from the former will give 6 i'm sure. anyone who disagrees please post working. it'll really help.
7. u = sqrt(1+x^2), udu/dx = x, dx = u/x * du substitution into the integral and you get 8u^2 du to integrate and your limits become u=1 to u = sqrt(2)
8. i have just realised my mistake, and to make things worse i have just realised that i had written the right thing and then just crossed it out and written something else. I want to kill myself right now
9. PC,

This is what it should have looked like.

I'm sure you can finish it off.

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