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# C2 watch

1. Attachment 638618638620

I understand everything until the 5/6th mark points, can anyone make sense on this?
Attached Images

2. (Original post by ckfeister)

Attachment 638618638620

I understand everything until the 5/6th mark points, can anyone make sense on this?
from the 4th mark to the 5th mark:
r + r + rθ = 4rθ
so if you put the two 'r's together:
2r + rθ = 4rθ
then if you subtract rθ from both sides:
2r = 3rθ
then if you divide both sides by r:
2 = 3θ
Then if you divide both sides by 3 to find θ:
θ = 2/3

from the 5th mark to the 6th:
sub in the value you just found for θ (which is 2/3) back into the equation you made for mark 2:
(1/2) x r2 x (2/3) = 12
a half times two thirds is one third so:
(1/3) x r2 = 12
multiply both sides by 3 to get rid of the third:
r2 = 36
square root both sides:
r = 6
3. (Original post by spofy)
from the 4th mark to the 5th mark:
r + r + rθ = 4rθ
so if you put the two 'r's together:
2r + rθ = 4rθ
then if you subtract rθ from both sides:
2r = 3rθ
then if you divide both sides by r:
2 = 3θ
Then if you divide both sides by 3 to find θ:
θ = 2/3

from the 5th mark to the 6th:
sub in the value you just found for θ (which is 2/3) back into the equation you made for mark 2:
(1/2) x r2 x (2/3) = 12
a half times two thirds is one third so:
(1/3) x r2 = 12
multiply both sides by 3 to get rid of the third:
r2 = 36
square root both sides:
r = 6

Attachment 638622638624

On this one, I get confused on how tan^2 x turns into tan^2x... how? question b.
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4. (Original post by ckfeister)

On this one, I get confused on how tan^2 x turns into tan^2x... how? question b.
What you've asked makes no sense but I assume you're asking how it goes to

Because if then the equations in both parts are equivalent.
5. (Original post by RDKGames)
Because if then the equations in both parts are equivalent.
I noticed seconds after asking...you know the normal me not reading properly.
6. (Original post by ckfeister)

Attachment 638622638624

On this one, I get confused on how tan^2 x turns into tan^2x... how? question b.

so basically the equations in both parts are exactly the same, only difference is they swapped all the x's and replaced them with 2θ just to mess with you - like you literally just have to sub in 2θ for x so if you do that, you already showed that the first equation was tan2 x = 3/2 so if you swap the x for 2θ to solve the next part, which you can do cos they're the same equation apart from the x, you can just write that tan2 2θ = 3/2 and solve from there

idk if you'll have been taught the same as me but anyway this is how id do it:
the interval in the question only has θ in the middle, but the equation you have is for 2θ, so you have to change the interval so that they match (so just multiply the interval by two so it becomes 0 < 2θ < 360

then you have to square root both sides of the tan2 2θ = 3/2 equation because you wanna work with just tan not tan squared - dont forget to use both the positive and negative roots.

i decided to continue explaining on paper lol

Attachment 638630638642Attachment 638630638642638600[attach]6.386306386426386e+23[/attach]
Attached Images

7. (Original post by spofy)
...
Well... you must be very bored or very keen to teach, can't say which one for sure
8. (Original post by RDKGames)
Well... you must be very bored or very keen to teach, can't say which one for sure
bit of both XD i was just glad there was finally a question i fully knew how to explain and answer because it's usually me asking the questions hahahaha
9. (Original post by spofy)

so basically the equations in both parts are exactly the same, only difference is they swapped all the x's and replaced them with 2θ just to mess with you - like you literally just have to sub in 2θ for x so if you do that, you already showed that the first equation was tan2 x = 3/2 so if you swap the x for 2θ to solve the next part, which you can do cos they're the same equation apart from the x, you can just write that tan2 2θ = 3/2 and solve from there

idk if you'll have been taught the same as me but anyway this is how id do it:
the interval in the question only has θ in the middle, but the equation you have is for 2θ, so you have to change the interval so that they match (so just multiply the interval by two so it becomes 0 < 2θ < 360

then you have to square root both sides of the tan2 2θ = 3/2 equation because you wanna work with just tan not tan squared - dont forget to use both the positive and negative roots.

i decided to continue explaining on paper lol

Attachment 638630638642Attachment 638630638642638600[attach]6.386306386426386e+23[/attach]
thx (doesn't allow 2 reps in 1 day)
10. (Original post by ckfeister)
thx (doesn't allow 2 reps in 1 day)
XD no problem

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