Question 858094: Which of the following statements are true?
a) For θ ∈ ] π/2 , π [ , both cos θ and sin θ are decreasing.
b) If 3π/2 ≤ θ ≤ 2π , then cos θ is decreasing.
c) In Quadrant 3, sin θ < 0 and cos θ < 0.
d) For θ ∈ [0, 2π] sin θ increases only when θ ∈ ] π/2 [
e) f(x) = cos x is increasing in the interval ]-2π,-π[
Can you please help me ? Thanks so much in advance:)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Which of the following statements are true?
a) For θ ∈ ] π/2 , π [ , both cos θ and sin θ are decreasing:: true
-----------------------------------------------
b) If 3π/2 ≤ θ ≤ 2π , then cos θ is decreasing.:: false
--------------------------------------
c) In Quadrant 3, sin θ < 0 and cos θ < 0.:: true
-------------------------------------------------------
d) For θ ∈ [0, 2π] sin θ increases only when θ ∈ ] π/2 :: false
---------------------------------------------
e) f(x) = cos x is increasing in the interval ]-2π,-π[:: false
---------------------------------------
Cheers,
Stan H.
================
Can you please help me ? Thanks so much in advance:)
|
|
|
