SOLUTION: Please help me the question is if sin theta= (2 sqrt5)/5 and cos theta=(-sqrt5)/5 what quadrant would the theta be in. For sin I have found that y=2 and r= sqrt5 For cos I have

Algebra ->  Trigonometry-basics -> SOLUTION: Please help me the question is if sin theta= (2 sqrt5)/5 and cos theta=(-sqrt5)/5 what quadrant would the theta be in. For sin I have found that y=2 and r= sqrt5 For cos I have      Log On


   



Question 854565: Please help me the question is if sin theta= (2 sqrt5)/5 and cos theta=(-sqrt5)/5 what quadrant would the theta be in.
For sin I have found that y=2 and r= sqrt5
For cos I have found that x= -sqrt5 and r= 5
How would this problem work if the r's arent the same

Answer by DrBeeee(684) About Me  (Show Source):
You can put this solution on YOUR website!
The answer to your question (r's are the same) is that they are the same! The difference is that you defined y = 2 for the sin function, but it is really y = 2 sqrt(5). Then the r for the sin is r = (sqrt5)*(sqrt5) or r = 5. In fact, the value of r must be the same!
The angle theta is in the second quadrant.