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C2- translation of sin,cos,tan &finding degrees. watch

1. My question is, how is one of the solutions 231?
Okay...I figured out how. I don't understand why. You add 180 to 131 and - 80 to get 231.

I followed the method in my book, I haven't a clue what's going one to be frank.

(I'm aware that 411 is wrong as its not in the 0-360 range)
Why would you add 180? And Not 360?

I know I sound really stupid, but I'm stuck. Will someone mind explaining this to me? And yes, I do realise this is supposed to be simple. *sigh*
2. (Original post by Questioness)
My question is, how on this bloody earth is one of the solutions 231?
Okay...I figured out how. I don't understand why. You add 180 to 131 and - 80 to get 231.

I followed the method in my book, I haven't a clue what's going one to be frank.

(I'm aware that 411 is wrong as its not in the 0-360 range)
Why would you add 180? And Not 360?

I know I sound really stupid, but I'm stuck. Will someone mind explaining this to me? And yes, I do realise this is supposed to be simple. *sigh*
Your mistake is where you've done 180 - 49 = 131.

You may be confusing this with sine : but that's not true for .

If you check on your calculator you'll see it's not equal to 0.66.

Are you able to correct your working? If you're still stuck, can you tell us which method you have been taught to find multiple trig solutions? E.g. CAST, using the graphs etc.
3. (Original post by notnek)
Your mistake is where you've done 180 - 49 = 131.

You may be confusing this with sine : but that's not true for .

If you check on your calculator you'll see it's not equal to 0.66.

Are you able to correct your working? If you're still stuck, can you tell us which method you have been taught to find multiple trig solutions? E.g. CAST, using the graphs etc.
Ahh, right. I was following the method in the textbook. It uses sin as an example. Do you take 49 away from 360, to get 311? Cos(311) =0.66

I'm following this method:
4. For cos you can just 360- first solution instead of 180 like you do for sin
5. Why do you not add 360 to 311.
It's just 311-80=231
Whereas a for 49, it's 49+360= 409-80 =329.
6. (Original post by Questioness)
Why do you not add 360 to 311.
It's just 311-80=231
Whereas a for 49, it's 49+360= 409-80 =329.

Does any of this not make sense?

You can solve each of the above equations and see which ones give you solutions in the range .
7. (Original post by notnek)

Does any of this not make sense?

You can solve each of the above equations and see which ones give you solutions in the range .
Makes perfect sense. Thanks.

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