SOLUTION: I've had some difficulties with these interval problems. I can't seem to come up with all of the correct answers. Usually each question has four answers but I can't seem to find th

Algebra.Com
Question 962972: I've had some difficulties with these interval problems. I can't seem to come up with all of the correct answers. Usually each question has four answers but I can't seem to find them.
Could someone please help me with the following question:
Find all solutions in the interval [0,2π): 4√2*sin(x/2)= -4
Enter the solutions in radians, or enter the null set.
Thank you in advanced.

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Find all solutions in the interval [0,2π): 4√2*sin(x/2)= -4
Enter the solutions in radians, or enter the null set.
-------
sin(x/2) = -4/(4sqrt(2)) = -1/sqrt(2)
-----------
For that sin value the angle must be in QIII or QIV
and must have a reference angle of pi/4.
------
In QIII you get x/2 = (5/4)pi
Then x = (5/2)pi
----
In QIV you get x = (7/4)pi
Then x = (7/2)pi
----------------------------
Cheers,
Stan H.

RELATED QUESTIONS

Hi I have two homework problems that I cannot seem to quite get. In class and with my... (answered by jim_thompson5910)
Hello, I have worked this problem out several times. I cannot seem to come up with the... (answered by AssassinXXX)
https://docs.google.com/document/d/e/2PACX-1vQytc1_zv8tSsDtgSW_muwH2juU0fELm_6xPfkm1MXabMk (answered by greenestamps)
Need help please. Question is: 12 3/4 ^2 /10 3/5 I’ve come up with two answers:... (answered by greenestamps)
I have one more equation that I am having problems with. Once again, the answer I came... (answered by dolly)
(5z+2)(z^2+3z+2) Please help, I cannot seem to come up with the correct... (answered by umnikmo,rfer,bucky)
I am trying to solve 8/(t-8) + 8/(t+8) and having problems. I've come up with three... (answered by ankor@dixie-net.com)
Can i get some help with these problems? Use an inequality to describe the interval of... (answered by stanbon)
Can you verify if I have arrived at correct answers to the below problems? Problem 1 (answered by MathLover1,mananth)