Let α be the second quadrant angle and | cos α 2|＝−cosα Then α, 2 2 is No.2______ Quadrant angle

Let α be the second quadrant angle and | cos α 2|＝−cosα Then α, 2 2 is No.2______ Quadrant angle

∵ α is the second quadrant angle, ᙽ α
2 is the first or third quadrant angle,
∵|cosα
2|＝−cosα
2，∴cosα
2 < 0, i.e. α
2 is the third quadrant angle
So the answer is: 3

Let a be the second quadrant angle, and the absolute value of COS (A / 2) be equal to the negative cos (A / 2). What quadrant angle is a / 2 Second, third, all right? I don't understand

Of course not! Because! Cos (A / 2)! = cos (A / 2), so the angle A / 2 must be the angle of the first and the second image. Because a is a binary image, a / 2 must be an angle of a term

If a is the second quadrant angle and | cos (A / 2) | = - cos (A / 2), then what quadrant is the angle A / 2 Thank you for the process!

First of all, it is judged that a / 2 is the first or third quadrant angle, and because cos (A / 2) = - cos (A / 2),
So a / 2 is the third quadrant angle

(sin θ cos θ, Tan θ sec θ) in the third quadrant, what quadrant is θ in?

third quadrant
sinθcosθ<0
tanθsecθ<0
tanθsecθ<0
(sinθ/cosθ)/(1/cosθ)<0
sinθ/(cos²θ)<0
Because cos 2 θ > 0
So sin θ < 0
From sin θ cos θ < 0
So cos θ > 0
sinθ<0
cosθ>0
So it's the fourth quadrant

The results showed that: (1 + sec α + Tan α) / (1 + sec α + Tan α) = (1 + sin α) / cos α

Let 2 β = α left = (1 + sec α + Tan α) / (1 + sec α - Tan α) = (COS α + sin α + 1) / (COS α - sin α + 1) = (COS α + 1 + sin α) / (COS α + 1-sin α) = (Cos2 β + 1 + sin2 β) / (Cos2 β + 1-sin2 β) = [2cos ^ 2 (β) + 2Sin β cos β] / [2cos ^ 2 (...)

Let θ be the third quadrant angle and | cos (θ / 2) | = - cos (θ / 2), then θ / 2 is the third quadrant angle___________ Quadrant angle

∵ θ is the third quadrant angle
∴π＋2kπ＜θ＜3π/2＋2kπ,k∈Z
∴π/2+kπ＜θ/2＜3π/4+kπ,k∈Z
Ψ / 2 is the second or fourth quadrant angle
∵|cos(θ/2)|=-cos(θ/2)
∴cos(θ/2)＜0
Ψ / 2 is the second quadrant angle

Given that a is the third quadrant angle and the absolute value of (COS A / 2) is equal to one cos A / 2, which quadrant is a / 2?

(2k+1)π

Given that the angle a is the angle of the second quadrant and the absolute value of sin a / 2 = - sin a / 2, then a / 2 is in the earth quadrant Mathematical function

If a is the second quadrant angle, then a / 2 can only be the first or third quadrant angle
Because the absolute value of sin a / 2 = - sin a / 2
Then a / 2 is in the third quadrant

Let a be the third quadrant angle and | Sina 2|=-sinA 2, then a 2 in () A. First quadrant B. Second quadrant C. The third quadrant D. Fourth quadrant

∵ angle a is the third quadrant angle, then a
2 may be the second or fourth quadrant angle,
Again, Sina
2|=-sinA
2, so Sina
2＜0，
∴A
2 is the fourth quadrant angle,
Therefore, D

Given that angle a is the fourth quadrant and the absolute value of sin angle A / 2 is equal to its opposite number, then what quadrant angle is a / 2

Fourth quadrant angle