1. ## trig

determine arcsin(sin(x)) for Pi/2 < x <3Pi/2

2. Originally Posted by dwsmith
I dont really understand whats going on in that thread =\
How would i calculate it in an exam? like with no calculator or stuff...

3. Lets start by saying y=arcsin(sinx) then.

Now if we take the sin of both sides, we have siny=sinx

What values of x and y in the interval will satisfy this equation?

4. Originally Posted by dwsmith
Lets start by saying y=arcsin(sinx) then.

Now if we take the sin of both sides, we have siny=sinx

What values of x and y in the interval will satisfy this equation?
all values?....

5. So if x=-pi and y=2, siny=sinx?

When x=y they will be equal. What angle does that occur at?

6. Originally Posted by dwsmith
So if x=-pi and y=2, siny=sinx?

When x=y they will be equal. What angle does that occur at?
dw... your rhetorical questions fail at life.
i worked it out myself

7. Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.

8. Originally Posted by dwsmith
Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.
no cause thats not the answer.....

9. Here is the proof pg 3.

x=arcsin(sinx)

I said say y=arcsin(sinx) and then ended with when y=x.

http://www.math.tamu.edu/~austin/section4_6.pdf

10. Originally Posted by dwsmith
Here is the proof pg 3.

x=arcsin(sinx)

I said say y=arcsin(sinx) and then ended with when y=x.

http://www.math.tamu.edu/~austin/section4_6.pdf
sorry can you stop failing? the answer is Pi -x..... i wanted someone to explain it...

11. You should work on your trig. Do you even know what the difference between it equaling x or pi - x?

It has to do with what side of the y axis you are on.

12. Originally Posted by dwsmith
Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.
dwsmith, I think you've got something wrong here. I think you are attempting to solve sin x = cos y.

13. Originally Posted by dwsmith
You should work on your trig. Do you even know what the difference between it equaling x or pi - x?

It has to do with what side of the y axis you are on.
i think you have to work on explaining things and actually getting the solution the person wants instead of waffling