help (2 Viewers)

[SB257426]

can i please borrow just 5 of your brain cells for fridays exam?

can i get some as well... i will need quadruple the amount tho

 

[synthesisFR]

omd pls dont tell me we need to know how y11 probability stuff works ik this sounds stupid but i dont remember it that well but hopefully its not needed for binomial

 

[synthesisFR]

im doing the 8 mark perms and combs and binomial mix in the 2020 hsc wtf is this
That means it wont be in our exam!!

 

[synthesisFR]

i have like 40 minutes to do it but im stuck on i)

 

[synthesisFR]

wait i got it lol i subbed in x=1 way too quick but u were meant to isolate 2ncn by isolating x^n coefficients

 

[synthesisFR]

this is 2022 hsc q12a
r we required to draw out the gradient line stuff to show that its that gradient?
r markers that pick. cuz all i did was just them relative to each other

 

[carrotsss]

View attachment 40769
this is 2022 hsc q12a
r we required to draw out the gradient line stuff to show that its that gradient?
r markers that pick. cuz all i did was just them relative to each other

you don’t need that much detail but having some level of ruled accuracy with them is good

 

[synthesisFR]

best way to do this?

 

[synthesisFR]

View attachment 40721View attachment 40722
could someone explain what they did for part ii lol
I got the same answer but i just did they collide so equated y = y then got V = 20sin(alpha) at collision, and just subbed in a=72 from i. But idk where they got the triangle and stuff from?

also can someone pls clarify this thx

 

[synthesisFR]

i lost a mark bc i didn't know what expected score is bc i forgot from 2u
@carrotsss which bits of 2u stats should i remember/know for binomial?

 

[carrotsss]

View attachment 40775
best way to do this?

- The derivative can never be negative because siny>=-1. This makes C impossible
- The derivative can never be greater than 2. This makes A impossible
- The derivative approaches 0, at which point the y value cannot increase further, so it can’t just go up forever. This makes D impossible
Hence, B

 

[carrotsss]

View attachment 40776
i lost a mark bc i didn't know what expected score is bc i forgot from 2u
@carrotsss which bits of 2u stats should i remember/know for binomial?

you just need E(X)=np and some logic to do this question, there’s not rlly any 2u stats involved?

 

[carrotsss]

View attachment 40721View attachment 40722
could someone explain what they did for part ii lol
I got the same answer but i just did they collide so equated y = y then got V = 20sin(alpha) at collision, and just subbed in a=72 from i. But idk where they got the triangle and stuff from?

the equation they used at the start of (ii) comes from the equating of x at the start, the triangle is just for the fact that it’s cos(arctan(3)), so to find an exact value you can use a triangle

 

[scaryshark09]

View attachment 40721View attachment 40722
could someone explain what they did for part ii lol
I got the same answer but i just did they collide so equated y = y then got V = 20sin(alpha) at collision, and just subbed in a=72 from i. But idk where they got the triangle and stuff from?

btw your method is also right

 

[Masaken]

10000% perms and combs are coming, last time it was asked was 2020

this topic will be the death of me idc idc why can't they just give like a hard binomial proof instead or smth pls

 

[synthesisFR]

- The derivative approaches 0, at which point the y value cannot increase further, so it can’t just go up forever. This makes D impossible
Hence, B

i dont get this?

 

[carrotsss]

i dont get this?

as y->3pi/2, sin(y)->-1 therefore dy/dx->0, and this means it stops going up and it can’t reach that point, hence an asymptote at 3pi/2

 

[synthesisFR]

so i basically managed to get this question right using my waffling skills and it matched the criteria perfectly,
but like
i literally dont understand why there is a sum when picking the groups of people.
like 0,2,...,2n why is there a sum adding all of these up cuz aren't each individual term a specific case for one outcome e.g 0,2,...,4 people etc

 

[raspberriesandpears]

carrotsss you are a god amongst men

 

[scaryshark09]

no, carrotsss is a farmer amongst men

i found him...