A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 4 years ago
Suppose θ is in the interval (180°, 225°). Find the sign of each function value.
a) Cos(2θ)
b) tan(θ90°)
c) sin(θ/2)
anonymous
 4 years ago
Suppose θ is in the interval (180°, 225°). Find the sign of each function value. a) Cos(2θ) b) tan(θ90°) c) sin(θ/2)

This Question is Closed

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0a) 2A puts you in 1st quadrant > cos(2A) is positive b) A90 puts you in 2nd quadrant > tan(A90) is negative c) A/2 puts you in 2nd quadrant > sin(A/2) is positive

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0How do you get to that? Is there any mathmatics behind it that will help me associate it so I can repeat this?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0this (rough) diagram should help\ dw:1328624954731:dw

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0so in first quadrant (090) all trig ratios are positive in 2nd (90180) sine is pos. cos and tan are neg. in 3rd (180270) tan is pos. sin and cos are neg. in 4th (270360) cos is pos. sin and tan are neg.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0also as an aid to memory you can memorise CAST  'Cos  All  Sin  Tan' these are the ratios which are positive in the quadrants : dw:1328625567936:dw eg 250 degrees  is in third quadrant : the tangent is positive, cos and sine are negative

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Yes this is great information. However, I still don't understand how you find: Suppose θ is in the interval (180°, 225°). Find the sign of each function value. a) Cos(2θ) : What would this be Cos(2*180)? b) tan(θ90°) c) sin(θ/2)
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.