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This is ruining my C2 prospects... Watch

1. PLEASE help me, whenever this type of question comes up, I simply just can't do it. I was on track to get 70ish/75 on my C2 test but these two questions completely ruin me, can someone give me advice on how to actually answer these types of questions or direct me to resources which can? I can do 8a by the way, it's the 8b and 8c type questions which trip me up.

Thanks
2. (Original post by Kyou)
PLEASE help me, whenever this type of question comes up, I simply just can't do it. I was on track to get 70ish/75 on my C2 test but these two questions completely ruin me, can someone give me advice on how to actually answer these types of questions or direct me to resources which can? I can do 8a by the way, it's the 8b and 8c type questions which trip me up.

Thanks
Is it that you struggle with finding the other solutions in the given period after getting the principal value?
3. For b just do inverse tan of 3, then list all solutions from a couple before 0 to a couple after 4pi to be safe. Then multiply each one by 2 and pick all the ones that still lie between 0 and 4pi.
4. For c you have a clue that tan is involved from part b. You need to spot that tan is achievable by dividing the whole equation by cos. The cos terms then cancel and the sin term becomes a tan term and then you can solve in same way as part b.
5. (Original post by Kvothe the arcane)
Is it that you struggle with finding the other solutions in the given period after getting the principal value?
Bingo.
I can get the first value of x, as it's fairly standard. However, I have no idea how to find any of the other solutions, especially in a period such as 0<x<4pi (which I can't understand why it has any relevance).
6. (Original post by Kyou)
PLEASE help me, whenever this type of question comes up, I simply just can't do it. I was on track to get 70ish/75 on my C2 test but these two questions completely ruin me, can someone give me advice on how to actually answer these types of questions or direct me to resources which can? I can do 8a by the way, it's the 8b and 8c type questions which trip me up.

Thanks
dam i remember the time i spent ages on these xD

the limit is

all you need to do is this

inverse tan then type in 3 then you'll get 1 answer
use a cast diagram and find areas where tan is positive(the A and T areas)
then figure out how to get the other value on cast diagram by doing something like + pi or -pi
then once you've done that and have 2 values remember your limit is so as long as your values fit into that area things will be ok, feel free to get a few more values by adding 2 pi to your current values....

don't forget you can always type your angle in radians back into your calculator and see if you get 3 back out or whatever the equation was equal to

Zacken for clarification
7. (Original post by Kyou)
Bingo.
I can get the first value of x, as it's fairly standard. However, I have no idea how to find any of the other solutions, especially in a period such as 0<x<4pi (which I can't understand why it has any relevance).
You may want to watch this and this.
8. (Original post by Zacken)
You may want to watch this and this.
The thing is I've watched them. However, I may have rushed through them. I'll take my time and see if it clicks.

Thank you
9. (Original post by Kyou)
The thing is I've watched them. However, I may have rushed through them. I'll take my time and see if it clicks.

Thank you
The second video is pretty clear, I think - you really want to sit down and watch it carefully then watch a few of his example videos and then for some of the problems, pause the video, attempt it and then see if you're right and if not, where you went wrong - post back and let us know how it goes (but that means a good 30 minutes of sitting down and attempting to understand/try out before coming back and posting! ) - good luck!
10. (Original post by Anon07079191)
For c you have a clue that tan is involved from part b. You need to spot that tan is achievable by dividing the whole equation by cos. The cos terms then cancel and the sin term becomes a tan term and then you can solve in same way as part b.
If you divide the whole equation by cos you will lose some valid solutions.
As it is factorised already you need to solve the bracket as you described but also solve for cos(X)=0

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11. (Original post by gdunne42)
If you divide the whole equation by cos you will lose some valid solutions.
As it is factorised already you need to solve the bracket as you described but also solve for cos(X)=0

Posted from TSR Mobile
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