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IB Math SL Paper 1


UmanngBharali

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6 minutes ago, elle98 said:

It asked for the minimum and i think it asked you to differentiate the surface area equation A(x) but I might be mixing things up.  

Oh yeah, optimization task, thanks :D It must have asked to differentiate because zero of the derivative should give the x coordinate (or side x of the cuboid) for the minimum of the original area function, and then you find the minimum area and calculate the cost to paint that area

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4 minutes ago, kevG said:

The last question about integrating using substitution was insane, I spent like 20 minutes on it and got it like the last minute... I got 3/2 for the very last question

How about you guys?

Yes, same, wasted my time on that one and actually what should be substituted was what was under the sq root, so that you get that du/dx=2x and then only integrate sq root of u... I was so angry for not seeing it.

Same, k=3/2

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14 minutes ago, kevG said:

The last question about integrating using substitution was insane, I spent like 20 minutes on it and got it like the last minute... I got 3/2 for the very last question

How about you guys?

Oh I feel so bad now. This question was a disaster for me, and despite enjoying the topics of integration/differentiation I struggle in this question, I'm definitely losing marks in this one  

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I found questions 8 and 9 to be pretty easy for Section B tbh, but I messed up the vector question and the Q10. How were we supposed to find k? I got k in terms of a and b because the area of the triangle was 0.5ab right?

And for the vector question, what did you guys get? Completely forgot what a unit vector was, ended up getting root11 and -root11 which I'm sure are wrong:hisfault:

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3 minutes ago, ibstudent77 said:

I found questions 8 and 9 to be pretty easy for Section B tbh, but I messed up the vector question and the Q10. How were we supposed to find k? I got k in terms of a and b because the area of the triangle was 0.5ab right?

And for the vector question, what did you guys get? Completely forgot what a unit vector was, ended up getting root11 and -root11 which I'm sure are wrong:hisfault:

you were asked in question 10, at the beginning, to express "b" in terms of "a" so you have an expression only with "a" and then it cancels down and you have 2/3k=1 in the end

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3 minutes ago, AnjaDe said:

you were asked in question 10, at the beginning, to express "b" in terms of "a" so you have an expression only with "a" and then it cancels down and you have 2/3k=1 in the end

I couldn't do that either :( I got a really long expression with x and y, how were we supposed to do that? I put it into the equation y-y1=m(x-x1)

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I had TZ1 and honestly it was the hardest thing I've done in a long time. There was a question that asked for values of K given the formula 3tan^4(x)+2k=-tan^4(x)+8ktan^2(x)+k. I literally lost it at that point. Any other TZ1s?

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5 hours ago, elle98 said:

 It was an absolute disaster, from the first question on it went downhill from there. the questions were just so different from what i learned in past paper questions especially the one with the cuboid. 

exactly! I did so many past papers and this one was so different, and much harder!

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2 hours ago, Ayaan said:

I had TZ1 and honestly it was the hardest thing I've done in a long time. There was a question that asked for values of K given the formula 3tan^4(x)+2k=-tan^4(x)+8ktan^2(x)+k. I literally lost it at that point. Any other TZ1s?

I'm TZ1. It was so awful. 

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5 hours ago, Kristina Rollová said:

I found this paper really good ( actually both papers). I did TZ2 and the only question which I slightly messed up was 7 with the unit vector. But overall it was testing really strong application knowledge which is great. 

Same, I found Question 7 very difficult because I couldn't find the m and n possibilities, but question 8-10 were easy for me :D 

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TZ1 here, pretty much got full marks on every practice I've done. This test literally killed me inside...

I think I got all the right answers, but I'm not really sure. Especially on that triangle one, I had two answers and I was 100% sure one was wrong, but I left it anyways because I'm silly and didn't cross it out. Now I'm kind of worried that they'll only grade the wrong one, but I'm not sure... :(

3 hours ago, Ayaan said:

I had TZ1 and honestly it was the hardest thing I've done in a long time. There was a question that asked for values of K given the formula 3tan^4(x)+2k=-tan^4(x)+8ktan^2(x)+k. I literally lost it at that point. Any other TZ1s?

It makes your whole life a lot easier if you use the substitution u=tan(x)^2. Makes solving for the quadratic and finding the discriminant a piece of cake! :D

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8 hours ago, ShootingStar16 said:

I got overly optimistic because most of section A was so easy and then the last two or so questions for section A and all of section B was just ajfodisjfioasjfsdj

Though I did get bits and pieces of section B :P 

Thats what usually happens to me haha. The questions in section A really boosts my morale but the section B is a slap on the face

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