Need help with this question (1 Viewer)

[Bloodstriker]

2 cos^2 x + cos x = 0

 

[SpiralFlex]

To better visualise,

Let





OR


OR

Assuming

 

[Bloodstriker]

wouldn't it = - 1/2
what program do you use to write like that?
anyways
2 cos x + 1 = 0
2 cos x = -1
cos x = -1/2

Thanks for the help. my teacher accidentally took my 3u book (and it had to be on friday, zomg) and i can't check answers

 

[SpiralFlex]

That is correct. I used Latex.

http://www.codecogs.com/latex/eqneditor.php

 

[Bloodstriker]

ok thanks. i'll probably post in this thread later tonight with a few questions i'm not sure on.

 

[SpiralFlex]

I and the rest of the community shall answer them for you.

 

[Bloodstriker]

Simplify: 8a^2 - 3a - a^2 - a
i get 7a(a-2)
book says 7a^2 - 2a
which is correct?

i can't believe i'm asking yr 7 questions -_-
i'd say my answer is more "simplified"

 

[SpiralFlex]

 

[ohexploitable]

That is correct. I used Latex.

http://www.codecogs.com/latex/eqneditor.php

No need for that anymore, just click on the "f_x" button when replying to a thread.

 

[SpiralFlex]

No need for that anymore, just click on the "f_x" button when replying to a thread.

Since when did they add that?

 

[Bloodstriker]

are the "harder factors" questions on page 67 of the coroneos 2u book at 3u level?

i can scan the questions and upload if you don't have the book

 

[SpiralFlex]

I don't have that book. I believe any quadratic or linear factorisation is simply Year 9 or 10 level.

 

[Bloodstriker]

isn't that what they ask in the first questions of exams?
"basic arithmetic and algebra"

 

[SpiralFlex]

Pretty much in Preliminary.

 

[SpiralFlex]

isnt this a trig equation? simply just learn the double angle formulas should suffice

There is no need for double angle formulae for this question.

 

[Bloodstriker]

what do you want to do in uni spiral?

Random question here:
when in general form (ax^2 + by^2 + c = 0), the gradient of the line is -b/a and the normal is a/b?

 

[SpiralFlex]

I want to do teaching.

 

[Bloodstriker]

Cool, i'm assuming maths?
Here's another one:
cot theta + tan theta/2 = cosec theta

 

[SpiralFlex]

First of all, that's not even a straight line. The general equation of a straight line is

To find the gradient:





So gradient of any straight line in that form is

Your second question is ambiguous.

Do you mean,



OR




I will assume the first one.


Let

By t formulae,









Off to study, goodbye.

 

[Bloodstriker]

the 1st equation.
Sorry i was looking at parabolas when i was writing that.

Thanks for the help.
How many hours a day do you study regularly? i.e not around exam time

Whenever you finish studying: How does the t result for cot X tan = 1+t^2/2t ?

and which is correct?
http://latex.codecogs.com/gif.latex?Does&space;(a-b)^2&space;-&space;c^2&space;=&space;(a-b+c)&space;(a+b-c)&space;OR&space;(a-b+c)(a-b-c)
my stupid textbook is defying the laws of maths