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# Maths C3 - Trigonometry... Help?? Watch

1. (Original post by RDKGames)
No need, the quadratic is all in terms of a single unknown variable and that's as simple as it gets.
OMG, I actually got it

Thank you thank you thank you thank you thank you

So happy!!
2. (Original post by Philip-flop)
OMG, I actually got it

Thank you thank you thank you thank you thank you

So happy!!
No problem, well done.
3. How have I been stuck on Chapter 6: Trigonometry of the Edexcel C3 Modular Maths Textbook for so long? Feel's like it's taking me ages to get through the book I was hoping to have finished all of it by now!
4. (Original post by Philip-flop)
How have I been stuck on Chapter 6: Trigonometry of the Edexcel C3 Modular Maths Textbook for so long? Feel's like it's taking me ages to get through the book I was hoping to have finished all of it by now!
Anything particular that you're stuck on?
5. (Original post by RDKGames)
Anything particular that you're stuck on?
Practically everything! :P

I'm constantly asking for help and still make stupid little mistakes. Feel like I have no hope of succeeding at A2 Barely even succeeded at AS!!

Feel like I need a tutor but really can't afford it :/
6. (Original post by Philip-flop)
Practically everything! :P

I'm constantly asking for help and still make stupid little mistakes. Feel like I have no hope of succeeding at A2 Barely even succeeded at AS!!
Just practice otherwise you'll carry those stupid little mistakes to the exam which is not what you want.
7. (Original post by RDKGames)
Just practice otherwise you'll carry those stupid little mistakes to the exam which is not what you want.
Yeah true. But sometimes I feel like I'm practicing loads and loads but still struggle later on :/

How do I make sure I don't lose motivation?
8. (Original post by Philip-flop)
Yeah true. But sometimes I feel like I'm practicing loads and loads but still struggle later on :/

How do I make sure I don't lose motivation?
Er, dunno. If I don't succeed in one question, I learn from it, and take on then next one because I want to get it right, I suppose. Exams are still a loooong way away so you'll get it by then.
9. (Original post by RDKGames)
Er, dunno. If I don't succeed in one question, I learn from it, and take on then next one because I want to get it right, I suppose. Exams are still a loooong way away so you'll get it by then.
Yeah, I guess I've just got to keep powering my way through and learn from my mistakes. But I seem to struggle to get the answer in the first place unless you're there prompting me like you have been

That's true, exams are a long way away, but in terms of the time that I have, I don't actually have a lot of study time
10. Ok so I'm stuck on Example 13 from chapter 6 of the Edexcel C3 Modular Maths Textbook part (a) ... For now :P ... Anyway I have a lot of questions to ask about this so if anyone could help I'd be more than thankful

1) What gives the impression that ... is the difference of two squares??

2) With this situation how do you find the difference of two squares, as I only know how to when an equation is in the form

3) How/where is the identity is being used??

Again, sorry for the ridiculously silly questions :/
11. (Original post by Philip-flop)
Ok so I'm stuck on Example 13 from chapter 6 of the Edexcel C3 Modular Maths Textbook part (a) ... For now :P ... Anyway I have a lot of questions to ask about this so if anyone could help I'd be more than thankful

1) What gives the impression that ... is the difference of two squares??

2) With this situation how do you find the difference of two squares, as I only know how to when an equation is in the form

3) How/where is the identity is being used??

Again, sorry for the ridiculously silly questions :/
1) Because both terms have the same even power and the whole expression is a difference. For any even power you can factor out a 2 which would make some arbitrary term to the power of 2, ie a square. So something like which is a square of some term to the third power.

2)

Also is not a form for a difference of two squares.. Difference of two squares is . So something like would indeed be a difference of two squares because

3) Second line. Second bracket equals 1.
12. (Original post by Philip-flop)
Ok so I'm stuck on Example 13 from chapter 6 of the Edexcel C3 Modular Maths Textbook part (a) ... For now :P ... Anyway I have a lot of questions to ask about this so if anyone could help I'd be more than thankful

1) What gives the impression that ... is the difference of two squares??

2) With this situation how do you find the difference of two squares, as I only know how to when an equation is in the form

3) How/where is the identity is being used??
A difference of two squares is this: .

Here you have .

Now the first bracket is but from your identity you know that so subtracting from both sides, we have .

So your factorisation becomes
13. (Original post by RDKGames)
3) Second line. Second bracket equals 0.
..
14. (Original post by Zacken)
..
lol...
15. (Original post by RDKGames)
1) Because both terms have the same even power and the whole expression is a difference. For any even power you can factor out a 2 which would make some arbitrary term to the power of 2, ie a square. So something like which is a square of some term to the third power.

2) try this.

Also is not a form for a difference of two squares.. Difference of two squares is

3) Second line. Second bracket equals 1.
Oh yeah. The difference of two squares never really made perfect sense to me until now. Thank you! I only knew how to solve the difference of two squares if it was written for example as... but that's as basic as I could work out

(Original post by Zacken)
A difference of two squares is this: .

Here you have .

Now the first bracket is but from your identity you know that so subtracting from both sides, we have .

So your factorisation becomes
Thank you!!! That step by step process has really helped me!! These new Trig Identities that are introduced in C3 are really intimidating but I'm glad you're there to help I just need to keep familiarising myself. Hopefully it won't be too much of a struggle
16. I can't help but keep you the good work mate. Oh and I can't help because I am learning C3 now
17. Trying to understand how for part (b) that...
<<<goes from...
...to this...

Edit: False alarm, I was being stupid. I realised that I just had to re-arrange using Trig Identities
Edit: False alarm, I was being stupid. I realised that I just had to re-arrange using Trig Identities

Edit: False alarm, I was being stupid. I realised that I just had to re-arrange using Trig Identities
18. (Original post by Philip-flop)
Trying to understand how for part (b) that...
<<<goes from...
...to this...
Because

and (from dividing both sides by cos squared)

Rearrange for sine squared, and tan squared, then sub them in.
19. (Original post by RDKGames)
Because

and (from dividing both sides by cos squared)

Rearrange for cos squared, and tan squared, then sub it in.
Thank you. I think all these Trig Identities are making me lose my mind which is why I've been making silly mistakes like that!
20. (Original post by Philip-flop)
Thank you. I think all these Trig Identities are making me lose my mind which is why I've been making silly mistakes like that!
As long as you remember you can pretty much derive the rest from it so you don't necessarily have to remember all of them.

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