# Math Help - Some sine equations

1. ## Some sine equations

sin x=-0.9
has solution x= 244.2
what is the other solution?? HELP

also

cos y=-0.3
y=107.5
wot else?

2. Remember that $\sin(\pi-x)=\sin x$ and $\cos(2\pi-x)=\cos x$

3. lol thats way beyond my league, can u give answers?

4. Originally Posted by sasha9193
sin x=-0.9
has solution x= 244.2
what is the other solution?? HELP

also

cos y=0.1
y=84.3
wot else?

Krizalid is correct. also, I should point out that there are infinitely many solutions since sine and cosine are periodic functions. you should state what interval you want them in

usually questions ask for the solution in $0 \leq \theta \leq 2 \pi$

Krizalid's solution gives the solution in $-2 \pi \leq \theta \leq 0$ as it stands now. you may have to do a little tweeqing

5. o yes sorry

6. Originally Posted by sasha9193
lol thats way beyond my league, can u give answers?
x is the angle you are given. $\pi$ = 180 degrees, $2 \pi$ = 360 degrees

try it

7. look above i just said the answers i need 0<x<360

could u give me answers this is beyond me but i need the answer

8. Originally Posted by sasha9193
look above i just said the answers i need 0<x<360

could u give me answers this is beyond me but i need the answer
the fact that users spit out answers sometimes makes people think that that's all we're here for. we don't like giving out answers if the user just mindlessly copies them down. if we see you make a valiant effort to understand we will help you. if you still don't get it, we will give you the answer and tell you to look over it carefully. please try to get it, it's for your own good. what specifically did you not understand from Krizalid's post?

9. look i am at very low level of maths at the moment, the question is only just understandable to me im learning but this type of question at the moment is beyond me i just need the answer

but i also understand your here to teach as well as just tell answers, but at the moment i am not up to the level you can start teaching me

10. Originally Posted by sasha9193
look i am at very low level of maths at the moment, the question is only just understandable to me im learning but this type of question at the moment is beyond me i just need the answer

but i also understand your here to teach as well as just tell answers, but at the moment i am not up to the level you can start teaching me
the answer to the first is 295.8 degrees (the sine one)

the answer to the second is 275.7 degrees (the cosine one)

11. the second one has changed slightly plz check second one at top

12. Originally Posted by sasha9193
the second one has changed slightly plz check second one at top
the new answer is 252.5

my final admonition: you will never get to the point where you can be taught and you can reason through something if you give up so easily. there is pretty much no one who gets up and understands everything without trying. you must work at it to get it. there are times when i spend hours, even days working on one problem, and i'm sure many of the other helpers here can testify to the same.