Math Ext 1 Predictions/Thoughts (4 Viewers)

[BAYPALS]

question 7 was C, cuz of the restriction on the sin^-1

there is no restriction!

 

[BAYPALS]

there is no restriction!

im assuming youre talking about 9?

Question 7 was the -asinx +bcosx that was D

 

[notme123]

im assuming youre talking about 9?

Question 7 was the -asinx +bcosx that was D

is that the one where the apex of a cos graph is shifted a bit to the left? i think i got that

 

[BAYPALS]

is that the one where the apex of a cos graph is shifted a bit to the left? i think i got that

correct

 

[Jojofelyx]

im assuming youre talking about 9?

Question 7 was the -asinx +bcosx that was D

it must be q9, and i think A?. I remember i when i solved it, it just going up and down and up and down cuz i just chucked in values outside of -pi and pi, and calc didnt gimme a "MATH ERROR".

 

[BAYPALS]

it must be q9, and i think A?. I remember i when i solved it, it just going up and down and up and down cuz i just chucked in values outside of -pi and pi, and calc didnt gimme a "MATH ERROR".

it was perfectly fine - thats what im saying 9 is A

 

[Jojofelyx]

it was perfectly fine - thats what im saying 9 is A

soooooo....when's the pdf coming along
plz xx

 

[oredbayz]

i got + 1-k i think if thats the issue but idk cant exactly remember, i just got what the q asked

yeah nah u are right just redid it

 

[Samarth shah]

someone please upload paper

 

[vishnay]

i got that as well, could it be a mistake on NESAs side

doubt it

everyone got 2a.b+(1-k)|b|^2

funnily enough me and my friend made the same exact mistake in the shm question in 4u which cost us like 2 marks lol

 

[Jojofelyx]

I guess we all await in tension and anticipation, for the dissemination of the 2021 HSC x1 paper on this website.

 

[Siwel]

curious did the newtons law of cooling de have a + or - k?

 

[Jerryclover]

curious did the newtons law of cooling de have a + or - k?

I got a positive which was weird but didn't have enough time to look back on it. You?

 

[JesusChriiii]

curious did the newtons law of cooling de have a + or - k?

do you need that tho? thought the question asked you to do it by integrating

 

[Siwel]

do you need that tho? thought the question asked you to do it by integrating

ye so i did but didnt know if i needed to specify whether k is negative or positive, ngl first time ive integrated a newtons law of cooling

 

[JesusChriiii]

ye so i did but didnt know if i needed to specify whether k is negative or positive, ngl first time ive integrated a newtons law of cooling

my k is negative i think. something like 1/8 ln(3/4)..？And i think i got 39 mins for it to heat to 20 degrees

 

[RedNalick]

my k is negative i think. something like 1/8 ln(3/4)..？And i think i got 39 mins for it to heat to 20 degrees

Yeah I got the same

 

[Siwel]

Yeah I got the same

but just solve for k and in the e^kt was it e^kt or e^-kt

 

[JesusChriiii]

but just solve for k and in the e^kt was it e^kt or e^-kt

Depends on if you flipped the fraction in the log

 

[Siwel]

Depends on if you flipped the fraction in the log

but wasnt the integral dt/dT = 1/k x 1/T-25 or whatever but 1/k out the front (positive 1/k)