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# Help trigonometry equation?? Watch

1. I need help? I know i got it wrong. But how?
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2. (Original post by naxiv)

I need help? I know i got it wrong. But how?
Where did the 120 come from?

180-30=150
3. (Original post by naxiv)

I need help? I know i got it wrong. But how?
I have no idea what are you doing
the solution should be

3x-15 =30 +360n where n=integer
3x-15 =150 +360n
4. (Original post by TeeEm)
I have no idea what are you doing
the solution should be

3x-15 =30 +360n where n=integer
3x-15 =150 +360n
Why and where did you get n from
5. (Original post by TenOfThem)
Where did the 120 come from?

180-30=150
What do you mean?
6. (Original post by naxiv)
Why and where did you get n from
sin and cos graphs repeat every 360
7. (Original post by TeeEm)
sin and cos graphs repeat every 360
You're not actually answering the question
8. your new range should be [-15,525]
9. (Original post by naxiv)
You're not actually answering the question
I just did

I have defined n as integer.
therefore you get more solutions in 360, 720, 1080, 1440 etc
thus 1x360, 2x360, 3x360, 4x360 etc
10. (Original post by Hasufel)
your new range should be [-15,525]
Yes I understand that bit
then what?
could you possibly give me the correct answer
11. where is the Sine negative? - in the 3rd and 4th quadrants of a cast diagram.

to each of these, you add odd a multiple of 360 deg, since the sin graph is periodic, and repeats every 360 deg.

The trick, for your range, is knowing when to stop adding multiples..

Then you have to subtract 15 deg from each, and / each by 3.
12. (Original post by naxiv)
What do you mean?
I mean sin120 is not 0.5

Sin150 is
13. (Original post by Hasufel)
where is the Sine negative? - in the 3rd and 4th quadrants of a cast diagram.

to each of these, you add odd a multiple of 360 deg, since the sin graph is periodic, and repeats every 360 deg.

The trick, for your range, is knowing when to stop adding multiples..

Then you have to subtract 15 deg from each, and / each by 3.
Why are you using negative sine?
14. Could someone just give me the answer?
(Original post by TenOfThem)
Why are you using negative sine?
15. (Original post by TenOfThem)
Why are you using negative sine?
apologies - i must be really short-sighted - read it as -1/2

(should`ve gone to specsavers)

OP - ignore my (wrong) hint.

apologies all - (i`ll go away now and get my girlfriend to put on her heels and walk up and down on my back!)
16. (Original post by naxiv)
Could someone just give me the answer?
I have done

Your working was fine APART from the fact that you used 120 instead of 150

What else do you need
17. Why isnt 15 incl. in the answer?
(Original post by TenOfThem)
I have done

Your working was fine APART from the fact that you used 120 instead of 150

What else do you need
18. (Original post by naxiv)
Why isnt 15 incl. in the answer?
19. (Original post by TenOfThem)
Here
Attached Images

20. (Original post by naxiv)
Here
Yes

Answers given are 15, 55, 135, and 175

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