• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

3 Unit Maths HSC Exam Revision (2 Viewers)

Trebla

Administrator
Administrator
Joined
Feb 16, 2005
Messages
8,401
Gender
Male
HSC
2006
...because you're differentiating a constant

What about this?

 

random-1006

Banned
Joined
Jun 25, 2010
Messages
988
Gender
Male
HSC
2009
...because you're differentiating a constant

What about this?


let f(t) = e^(t^2)
= d/dx [integral f(t) dt between limits]
= d/dx [ F(x^2) - F(0) ]
= 2x F ' (x^2) - 0 * F ' (0)

but F ' (t) = f(t)

so answer = 2xe^(x^4)

but thats not 3 unit or 4 unit
 
Last edited:

bouncing

Member
Joined
Mar 19, 2010
Messages
497
Gender
Female
HSC
2010
hey guys lol this is such a stupid question but how do you do auxilliary/subsidiary angles again?
this is a sub/aux question right?

@= alpha (cbf using latex)

4cos@+3sin@=1

find @
 

random-1006

Banned
Joined
Jun 25, 2010
Messages
988
Gender
Male
HSC
2009
hey guys lol this is such a stupid question but how do you do auxilliary/subsidiary angles again?
this is a sub/aux question right?

@= alpha (cbf using latex)

4cos@+3sin@=1

find @

Let 4cos@ + 3sin@= Acos(@ + a)
therefore 4cos@ + 3 sin@= Acosacos@ - Asinasin@

equating coeffiencents

Acosa= 4 --- 1
Asina= -3 --- 2

sqaure and add 1 and 2
A^2= 25, A= 5, take positive case

now cos is positive and sin is negative in the fourth quadrant.

so we have cosa = 4/5 , related angle = 36.9 degrees, as we are in fourth quadrant, 360- 36.9= 323.1

so we have 5cos(@ + 323.1) = 1
cos(@ + 323.1) = 1/5 etc
 

Hayzazz

Pig Member
Joined
Sep 2, 2009
Messages
345
Location
Sydney
Gender
Male
HSC
2011
Shouldn't 4cos@ + 3sin@ = Acos(@ - a) ? Not Acos(@ + a)

EDIT:
Oh wait nvm it doesn't make a difference :\
 
Last edited:

random-1006

Banned
Joined
Jun 25, 2010
Messages
988
Gender
Male
HSC
2009
Shouldn't 4cos@ + 3sin@ = Acos(@ - a) ? Not Acos(@ + a)

im fairly sure from memory you can pick either. ie instead of getting 5cos(@+330) , you will get 5cos(@-30) ie 360 has been subtracted

but yes the cos(@-a) would look better, i wasnt think bout that
 

x jiim

zimbardooo.
Joined
Jul 10, 2008
Messages
477
Gender
Female
HSC
2010
Uni Grad
2018





sorry about the awkward spacing, this is my first time using latex.

Solve
 

mysticwater

Member
Joined
Jan 12, 2010
Messages
36
Gender
Male
HSC
N/A
Not sure for the above question but i think you use logs and u'll get a ans with d.p?

The gradient of a curve is given by y'= . the curbe passes through points (0,2)

Find the question of the curve. How would u answ this?
 

Users Who Are Viewing This Thread (Users: 0, Guests: 2)

Top