3 Unit Maths HSC Exam Revision (1 Viewer)

Trebla

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...because you're differentiating a constant

What about this?

 

random-1006

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...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
 
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bouncing

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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

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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

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Shouldn't 4cos@ + 3sin@ = Acos(@ - a) ? Not Acos(@ + a)

EDIT:
Oh wait nvm it doesn't make a difference :\
 
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random-1006

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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

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

Solve
 

mysticwater

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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?
 

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