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Products as sums or differences (1 Viewer)

Carrotsticks

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Lol, I fudged my working in a practice topic test I was doing once for 2U and I got the mark for it :D
But I reading this thread I was freaking out because I've never heard of the product as sums or differences let alone done it in class. My question now is, could they ever ask a question on this in the HSC and if so, is it best I learn it? My textbook is maths in focus :mad: so I don't think it has it in there.
Highly unlikely they will ask for it in the HSC.

If they do, they will at least first ask you to prove the identity (which is simple enough).
 

Kimyia

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Highly unlikely they will ask for it in the HSC.

If they do, they will at least first ask you to prove the identity (which is simple enough).
Ok, thanks :) Am I screwed with just using maths in focus??....I think my library has Cambridge which I'm going to borrow once we get back.
 

Carrotsticks

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Ok, thanks :) Am I screwed with just using maths in focus??....I think my library has Cambridge which I'm going to borrow once we get back.
Maths in Focus only covers the basic questions for every topic. Enough for probably a low Band 6/high band 5

If you want difficult questions, get the Cambridge book.
 

Kimyia

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Maths in Focus only covers the basic questions for every topic. Enough for probably a low Band 6/high band 5

If you want difficult questions, get the Cambridge book.
Seriously? Because scraping an E4 is my goal atm :)
 

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Can someone explain the mathmatics extension bands??
like e4 , e3 is band 5 or 6 etc..?
lol
 

Kimyia

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I think E4 is >45, E3 >35, E2 >25
 

812

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Can someone please help me with this question?

Prove the identity

(2cos0.5X - 1 - cosX)/(2cos0.5X + 1 + cosX) = (1 - cos0.5X)/(1 + cos0.5X)



(farrrrrrr....it's 12:40 on a Sunday night during school holidays.....and I'm doing maths.)
 
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SpiralFlex

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Can someone please help me with this question?

Prove the identity

(2cos0.5X - 1 - cosX)/(2cos0.5X + 1 + cosX) = (1 - cos0.5X)/(1 + cos0.5X)




(farrrrrrr....it's 12:40 on a Sunday night during school holidays.....and I'm doing maths.)






 
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812

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Wow thanks....you guys are good. How did you guys think of using the double angle formula on cosX? How do I think like that?

Anyway, I'm stuck on another question.

Prove the identity

(1 - tanXtan2X) / (1 + tanXtan2X) = 4cos^2(X) - 3
 
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Carrotsticks

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We knew to use it because the RHS had half angle formula only, implying that we had to 'break down' the 'double angle' cosX to its half angle form with cos0.5x.

Use the terms of the question as a clue as to what to do

This will help you greatly with proving Trig Identities.

 

812

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We knew to use it because the RHS had half angle formula only, implying that we had to 'break down' the 'double angle' cosX to its half angle form with cos0.5x.

Use the terms of the question as a clue as to what to do

This will help you greatly with proving Trig Identities.

Thank you.

I got to the 4th step previously and got stuck....
 

Drongoski

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Carrots

I just love the compact and very crisp mathematical type-script. How do you do that? I only know a bit of TeX and can't get it that nice.
 

Carrotsticks

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Carrots

I just love the compact and very crisp mathematical type-script. How do you do that? I only know a bit of TeX and can't get it that nice.
I'm actually not using LaTeX.

I'm using a program called 'Math Type', which is extremely easy to use (and requires much less skill than TeX). They have all the templates for fractions, matrices etc ready for you, and you just need to fill in the details.

Once you've typed it all out in the program, simply copy paste all of it into a Microsoft Word document.

It appears in the word document as a .gif file all nice and ready.

However, MathType also has a function where you can type in LaTeX and it will automatically appear in proper Math form.
 

812

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I'm actually not using LaTeX.

I'm using a program called 'Math Type', which is extremely easy to use (and requires much less skill than TeX). They have all the templates for fractions, matrices etc ready for you, and you just need to fill in the details.

Once you've typed it all out in the program, simply copy paste all of it into a Microsoft Word document.

It appears in the word document as a .gif file all nice and ready.

However, MathType also has a function where you can type in LaTeX and it will automatically appear in proper Math form.
Did you have to buy it?
 

Carrotsticks

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Nah, you can have an unlimited free demo.

However, the demo has fewer templates and quick-shortcuts, so it takes a bit more time typing it out.

Nevertheless, things can be written out much more quickly than LaTeX.
 

812

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Nah, you can have an unlimited free demo.

However, the demo has fewer templates and quick-shortcuts, so it takes a bit more time typing it out.

Nevertheless, things can be written out much more quickly than LaTeX.
Can you still recall the download link for it? :D
 

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