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Maths Ext 2 predictions (1 Viewer)

ExtremelyBoredUser

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i capped at 80 raw a while ago and have not been bothered to improve cause i need like 10 extra raw marks to get 0.05 better atar
diminishing returns so yh ull be fine but doesnt hurt to improve if u can cuz more marks more confidence for next exam
 

scaryshark09

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how do you do part 1 and 3? and why is part 2 3 marks when its the easiest one?
 

ExtremelyBoredUser

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also i dont know how to do pulley questions (idk what tension is and how it works) and i dont know how to do incline planed questions
1. choose whcih direction is +ve if not specified e.g up +ve, east +ve rest -ve
2. create a force diagram (gravitational, tension etc)
3. set up equations for both sides e.g m1g - m1a = T1
4. equate and try to find what u want
 

carrotsss

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i stg it is actually impossible to keep up with bos rn like I’ve been spending way to much time here and yet I still have 3 pages of unread new threads
 

liamkk112

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View attachment 40274
how do you do part 1 and 3? and why is part 2 3 marks when its the easiest one?
For i) :
magnitude of op^2 = 1 = x^2 + y^2 + z^2, then x^2 <= |x|, same for y, z as if |OP| = 1 then copmonents are less than one and squaring number less than one means get smaller. then just plug in and u get the inequality

For iii):
let a = (|x|,|y|,|z|), b= (1,1,1) (REASONING: u would get sqrt3 on RHS, and then LHS would be same as in part 1) then, RHS = sqrt(3) * 1 (b.c. |a| =1 as lies on sphere of radius 1) and LHS =|x| + |y| + |z| (can omit bigger abs value bc inside is posiitve), hence |x| + |y| + |z| <= sqrt(3)
 

carrotsss

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you just sorta gotta common sense a lot of it

for quadrant 2, x is always negative whilst the argument is always positive so that’s obviously not included

for quadrant 4, x is always positive whilst the argument is always negative so that’s always included.

for quadrant 1, when x is greater than pi/2 it’s included since the argument won’t exceed pi/2 there, but the region from 0 to pi/2 is a little more complicated. tan(theta)=y/x, but theta>=x, so tan(theta)>=tan(x) and therefore tan(x)<=y/x. hence xtan(x)>=y and from there the rest is trivial, just graph xtan(x)=y within that region

for quadrant 3, the argument is always less than -pi/2 so any x values greater than or equal to that are ofc included. then beyond that it’s the same deal as previously, make an equation with y and x using the fact that theta>=x and you’re good
 

SB257426

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Nah like how did he find it (like what are his opinions on it) cos i did it and i jus wanna see if they can resonate or if its just an individual human experience
OHH bro..... lol...

the human condition has taught us that multiple personalities induce distinct responses to complex situations thus u may not be able to resonate with his experiences
 

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