Mathematics Question Thread

[Shadowxo]

Thanks.

For the second one, the equation is given as 2x^2 - (4k+1) + 2k^2 - 1 = 0. Shouldn't there be an x next to the -(4k+1) (so the original equation is 2x^2 - (4k+1)x + 2k^2 - 1 = 0) so that I know that -(4k+1) is b? If not, how do I know what's b and what's c? I should have explained this better earlier.

It looks like there was supposed to be an x there, they just didn't put it in, so b would be -(4k+1). If there was no 'x' term then b would be 0.

[RuiAce]

Thanks.

For the second one, the equation is given as 2x^2 - (4k+1) + 2k^2 - 1 = 0. Shouldn't there be an x next to the -(4k+1) (so the original equation is 2x^2 - (4k+1)x + 2k^2 - 1 = 0) so that I know that -(4k+1) is b? If not, how do I know what's b and what's c? I should have explained this better earlier.

Ah. Whilst technically that should be a part of the constant, I believe whoever wrote that paper made an extremely clumsy typo and forgot the x.

[_____]

Ah. Whilst technically that should be a part of the constant, I believe whoever wrote that paper made an extremely clumsy typo and forgot the x.

Whew, glad I wasn't being dumb. Didn't think James Ruse (2015 paper) of all schools would make a mistake like that. They didn't even note it in the marker's comments lol

[RuiAce]

Whew, glad I wasn't being dumb. Didn't think James Ruse (2015 paper) of all schools would make a mistake like that. They didn't even note it in the marker's comments lol

You shouldn't discard that possibility just because they're the #1 school. These mistakes happen all the time.

[Thebarman]

Any tips on how to integrate functions? I'm completely lost when it comes to it.

[RuiAce]

Any tips on how to integrate functions? I'm completely lost when it comes to it.

There's only so many functions to integrate in 2U.

Please provide examples indicating where the difficulty lies.

[Thebarman]

Say t /(t^2 + 3). How would I integrate that?

For a while, I tried using the quotient rule here before realising that the rule didn't apply for integration.

[RuiAce]

Say t /(t^2 + 3). How would I integrate that?

For a while, I tried using the quotient rule here before realising that the rule didn't apply for integration.

Usually, what constitutes "almost the same" is when you're out by a factor of a constant.


Note that we fudge by multiplying by 2, but then multiplying by 1/2 to cancel it out. This is effectively equivalent to multiplying by 1, so we have not changed the question.

[Thebarman]

Ahhhh. Yeah, that makes sense.

I'm still ending up with answers that are slightly off when it comes to these kind of questions. With this question, I'm off by a few decimals, but it screws up the following answers.

A particle's acceleration is given by a=2/(t+3)^2 with the particle initially resting at 2 Ln(3) m to the left of the origin. Evaluate the velocity after 2 seconds.

I integrated it and reached ln(t+3) + C, but everything went fuzzy afterwards. Where would I go from here?

[RuiAce]

Ahhhh. Yeah, that makes sense.

I'm still ending up with answers that are slightly off when it comes to these kind of questions. With this question, I'm off by a few decimals, but it screws up the following answers.

A particle's acceleration is given by a=2/(t+3)^2 with the particle initially resting at 2 Ln(3) m to the left of the origin. Evaluate the velocity after 2 seconds.

I integrated it and reached ln(t+3) + C, but everything went fuzzy afterwards. Where would I go from here?

[sophiegmaher]

Hey so I'm confused on part (ii) of the attached question. I've looked through the answers but I still don't get it!

[RuiAce]

Hey so I'm confused on part (ii) of the attached question. I've looked through the answers but I still don't get it!

Already addressed by Jake in the compilation.

[jaskirat]

why does my question keep getting removed?

[RuiAce]

why does my question keep getting removed?

Because I have already moved it elsewhere. Like stated, please refrain from spam posting.

[jaskirat]

where did you move it to?