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Maths AQA Spec B Calc thread

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To clear it up these were the answers for the harder questions

The CosA was 132 degrees. (using reverse of cosine rule by re-arranging it)
Algebraic fractions was -0.78 and -2.78
The guy was too tall for the tent (can't remember what I exactly did)
Oh yeah the similar shapes area was where you had to bring the fact it was volume into the question, and cube root it and do things, wasn't just using the ratio they had given you of the length!
Histogram was nice and simple.
The area of the 40x^2 was easy, just divide it by 8 to get the 5x^2 area.
The 49c^2-d^2 was using the method of (7c+d)(7c-d) where -7cd and +7cd cancel each other out nicely.
For the bread types, you know there were ratios of 10 across the breads, 6:1:3, so 130/10 = 13, and then just do 6x13 e.t.c

Hope this clears it up with some of you guys :smile:

cube root it? I said that the linear scale factor was 1.25 (15/12) and so the volume scale factor would be 1.25^3, and then multiplied the volume by 1.25^3 :s-smilie:

Is that wrong? :/

Reply 61

Jennoooo

What was the answer to x^2 +10x + b = (x-a) - 7? I realy struggled with it..

Reply 62

Miz9

Original post by Halzy1234

For the bread one I got 78 , 13 & 39

Posted from TSR Mobile

Same! What about the nail and screw question? I think it was linked in to upper and lower bounds

Reply 63

par71

Original post by surina16

20 and 12?

That's what I got and I checked the solutions to ensure the values added up correctly to 180 and 360.

The bearings one involving Pythagoras' Theorem came to 90 km.

Reply 64

AlexMB9

Original post by surina16

cube root it? I said that the linear scale factor was 1.25 (15/12) and so the volume scale factor would be 1.25^3, and then multiplied the volume by 1.25^3 :s-smilie:

Is that wrong? :/

That actually makes more sense than mine, this was something I didn't cover in class to an extent so I worked it out. What did you get as your answer if you can remember? Yeah your probs right aha, I'm generally better at trig and algebra.

Reply 65

Miz9

Original post by surina16

cube root it? I said that the linear scale factor was 1.25 (15/12) and so the volume scale factor would be 1.25^3, and then multiplied the volume by 1.25^3 :s-smilie:

Is that wrong? :/

That's exactly what I did too😱

Reply 66

starstudent7

Original post by surina16

I think I got 90km (if that was the one with the 2 boats). And for the rectangle I got 180 :smile:

I got 90 degrees first but then I changed it to 120 degress because I couldn't really give 90 to two significant figures so I changed it. :redface:

Then for the rectangle I got something in the thousands but lots of people in my school got 180. I don't know how people worked it out. I just figured out that x=36 and then substituted it in so I got the wrong answer. :frown:

Reply 67

studentshavefun

How did u do the bounds question

Reply 68

Jennoooo

Original post by dikshaun

How'd it go!

I got everything except the second last algebraic fraction, and the factorise 49(c-d) one.. anyone get them?

I think the answer was (7c-d)(7c+d)

Reply 69

AlexMB9

just times everything by 2.5 for first question lmao

Reply 70

starstudent7

Original post by surina16

Idk right now - it seems to be a 50/50 split between the 2 answers! :biggrin:

And thank you haha but not really (you seem to be way better at maths lmao) :colondollar:

IKR

Ur welcome, but it's true. :wink:

Reply 71

TheConfusedMedic

Original post by AlexMB9

1400*1.25^3 = 2734.375 so I just rounded it I think.
Not sure if it's right either tbh since it's not something we've really covered (they like to do all the harder stuff like vectors and algebraic proof but not the 'easier' topics :colonhash: