Hi! I am confused about this. Additionally, we cannot use a calculator.
Here is the problem:
cos(theta)=-1/3, (pi/2)<theta<pi
So I know how to find tan, cot, csc, and sec, if I could only find out sin(theta). I also know that cos(pi/2)=cos(90)=0, and that cos(pi)=cos(180)=-1.
Does this possibly mean that, since -1/3 is a third of the difference between -1 and 0, that theta is (90+30), because 30 is a third of the difference between 180 and 90? If so, how would you find sin(120)?
Here is the problem:
cos(theta)=-1/3, (pi/2)<theta<pi
So I know how to find tan, cot, csc, and sec, if I could only find out sin(theta). I also know that cos(pi/2)=cos(90)=0, and that cos(pi)=cos(180)=-1.
Does this possibly mean that, since -1/3 is a third of the difference between -1 and 0, that theta is (90+30), because 30 is a third of the difference between 180 and 90? If so, how would you find sin(120)?