Expert: Paul Klarreich - 1/2/2007

Question
Please help me!!

X is between 0 degrees and 360 degrees (meaning show answer in degrees??)
3sin(x + 20) degrees = -1

3sin(x + 20)= -1
---I divided both sides by 3---
sin(x+20)= -1/3
Now what? I think that I need to find a reference angle or something like that...

Would you show me exactly what to do step-by-step? however, any help that you can offer would be GREATLY appreciated. Thank you in advance for your time.

Answer
Hi, Jon, ... I mean, Christie,

Do these two questions look similar:
------------- FIRST QUESTION ----------------
c) X is between 0 degrees and 360 degrees (meaning show answer in degrees??)
3sin(x + 20) degrees = -1

3sin(x + 20)= -1
---I divided both sides by 3---
sin(x+20)= -1/3
Now what? I think that I need to find a reference angle or something like that...

Please help me!!
------------- SECOND QUESTION ------------------
c) X is between 0 degrees and 360 degrees (meaning show answer in degrees??)
3sin(x + 20) degrees = -1

3sin(x + 20)= -1
---I divided both sides by 3---
sin(x+20)= -1/3
Now what? I think that I need to find a reference angle or something like that...

Please help me!!
-------------------------------------------

Did you lose the answer I sent the last time?  Well, if you did, then here it is again:

-------- ANSWER SENT EARLIER -----------------
C. 3sin(x + 20)= -1

  sin(x+20)= -1/3

So far, so good.  Now you will have to find a reference angle.  Like this:

1/3 = 0.3333..

x+20 = INV SIN (0.3333) = 19.5 (degrees)

Angle in Q3:  189.5 = x + 20,  x = 169.5
Angle in Q4:  340.5 = x + 20,  x = 320.5