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Original post by KloppOClock
what is this
intergral.png


Ah, I know which question you're talking about - it's the multiple choice question with 3 different integrals, yes?

Just so you know, for that question, you don't need to evaluate the integrals at all. You technically can, but it's not on the syllabus and it'll probably take longer.

Some more help if you need it:

Spoiler

Original post by lewman99
Ah, I know which question you're talking about - it's the multiple choice question with 3 different integrals, yes?

Just so you know, for that question, you don't need to evaluate the integrals at all. You technically can, but it's not on the syllabus and it'll probably take longer.

Some more help if you need it:

Spoiler


i just dont get why the dx is above the cos3x
Can anyone help explain G of the multiple choice questions from 2011?
Thank you
Original post by RichE
Yes, the bold is right.

Well the next ones are hyperbolae, can you sketch those?

And if you think about it you only need those hyperbolae to answer the rest of the second part.


Hey, I still really can't follow the question feel so stupid. Im guessing that the max for x^2+y^2+4xy is 3? (Probably wrong) since its = (x+y)^2+2xy and (x+y)^2 is dominant term and we know the max for x+y so we just sub it in to get 3? I don't really know how to do the next 2 parts though, would you please guide me in the right direction?
Original post by Moogle679
Can anyone help explain G of the multiple choice questions from 2011?
Thank you


think of it as a compound function
Reply 265
Original post by danielhx
Hey, I still really can't follow the question feel so stupid. Im guessing that the max for x^2+y^2+4xy is 3? (Probably wrong) since its = (x+y)^2+2xy and (x+y)^2 is dominant term and we know the max for x+y so we just sub it in to get 3? I don't really know how to do the next 2 parts though, would you please guide me in the right direction?


You're overcomplicating things. When is x^2+y^2 largest, when is xy largest, is there somewhere where both these things happen?
Reply 266
Original post by Moogle679
Can anyone help explain G of the multiple choice questions from 2011?
Thank you


What is the function f for inputs between -1 and 0? Note x^2-1 is in that range.
2.png
dont get this
Anyone else find the specimen paper B much easier that the other papers??
Original post by KloppOClock
think of it as a compound function


Original post by RichE
What is the function f for inputs between -1 and 0? Note x^2-1 is in that range.


IMG_1261.jpg

This is what I did but I'm pretty sure it's wrong, nothing is clicking with me for this question for some reason
Original post by Moogle679
IMG_1261.jpg

This is what I did but I'm pretty sure it's wrong, nothing is clicking with me for this question for some reason


looks right
Reply 271
Ahhhh I'm so ***king nervous But not studying 👻🙀
Original post by KloppOClock
x
dont get this

Spoiler

Original post by 17lina
Ahhhh I'm so ***king nervous But not studying 👻🙀


only 23 days left already, time is going so fast :eek:
Original post by DylanJ42

Spoiler



but surely thats just calculating the number of possibilities for when you are doing the function
figfjgfk\displaystyle f^{i}gf^{j}gf^{k}

what about if you did something like g2fm\displaystyle g^{2}f^{m}

EDIT: nvm i get it now, j and k would be zero in that case, I understand now
(edited 7 years ago)
Original post by KloppOClock
i just dont get why the dx is above the cos3x


0π/8 ⁣dxcos3x\int_0^{\pi/8} \! \frac{\mathrm{d}x}{\mathrm {cos} 3x} can just be treated as 0π/8 ⁣1cos3xdx\int_0^{\pi/8} \! \frac{1}{\mathrm {cos} 3x} \, \mathrm{d}x, as it is basically treating dx\mathrm{d}x as a scalar multiple, thus being on the numerator:

1cos3x×dx=dxcos3x\frac{1}{\mathrm {cos} 3x} \, \times \mathrm{d}x = \frac{\mathrm{d}x}{\mathrm {cos} 3x}
Original post by some-student
0π/8 ⁣dxcos3x\int_0^{\pi/8} \! \frac{\mathrm{d}x}{\mathrm {cos} 3x} can just be treated as 0π/8 ⁣1cos3xdx\int_0^{\pi/8} \! \frac{1}{\mathrm {cos} 3x} \, \mathrm{d}x, as it is basically treating dx\mathrm{d}x as a scalar multiple, thus being on the numerator:

1cos3x×dx=dxcos3x\frac{1}{\mathrm {cos} 3x} \, \times \mathrm{d}x = \frac{\mathrm{d}x}{\mathrm {cos} 3x}


Okay, I didn't know you could treat dx\displaystyle dx like that, thanks. Are there any other ways you can use dx\displaystyle dx where its notf(x)[x]dx\displaystyle f'(x) [x] dx or f(x)[dx/x]\displaystyle f'(x) [dx/x] ?
(edited 7 years ago)
Also, is anyone here going to that MAT support event thing tomorrow at manchester uni?
Original post by KloppOClock
Also, is anyone here going to that MAT support event thing tomorrow at manchester uni?


No, but could you do me a favour and let me know what they say? Thanks!
Can someone explain MAT15 Q3 Part VI?

I have absolutely no idea where they got anything in their solution from.