If 1 + sin θ - cos θ = 0, then what quadrant angle is θ

If 1 + sin θ - cos θ = 0, then what quadrant angle is θ

Because sin θ + cos θ = 1, sin θ < 0, cos θ > 0, and θ is in the fourth quadrant

If a is the second quadrant angle and satisfies cos (A / 2) - sin (A / 2) = radical sign {(sin (A / 2) - cos (A / 2))} A / 2 is the second quadrant angle Third quadrant angle

Isn't it a half a=

A is the second quadrant angle cos (A / 2) - sin (A / 2) = under radical {(sin (A / 2) - cos (A / 2))} What quadrant is a / 2 in

Cos (A / 2) - sin (A / 2) = under radical {(sin (A / 2) - cos (A / 2))} = \ \ cos (A / 2) - sin (A / 2)\
therefore
cos(a/2)-sin(a/2)≥0
sina/2≤cosa/2
A is the second quadrant angle, that is 2K π + π / 2 < a < 2K π + π
kπ＋π/4＜a/2＜kπ＋π/2
K = even, a / 2 in the first quadrant, Sina / 2 ≥ cosa / 2, wrong
therefore
K = odd
A / 2 is in the third quadrant

If α is the angle of the second quadrant and cos α / 2 = - radical 1-cos 2 (π / 2 - α / 2), then α / 2 is the angle of the second quadrant

Thinking: α is the angle of the second quadrant, that is 2K π < α 2K π + π, ﹤ K π < α / 2 ﹤ K π + π / 2, (K ∈ z), that is, α / 2 is in the first or third quadrant. On the other hand, cos α / 2 = - radical 1-cos 2 (π / 2 - α / 2) = - root sign cos 2 (α / 2) = - |

If cos (α - β) = 5 / 5 under the root, Cos2 α = 10 / 10 under the root, and α and β are acute angles and α < β, then α + β

Because: α and β are acute angles and α

Let a be the second quadrant angle, P (x, Radix 5) be a point on its final edge, and cosa = root 2x divided by 4,

If P (x, y) is a point on the terminal edge of a, then cosa = x / √ (x? 2 + y?)
The solution of √ 2x / 4 = x / √ (x? 2 + 5) is x = ± √ 3
∵ A is the second quadrant angle
∴x=-√3 ∴cosa=-√6/4
sina=√1-cos²a=√10/4

1-cosa / 1 + cosa + 1 + cosa / 1-cosa under root, where a is the fourth quadrant angle 2

=(1-cosa+1+cosa)/(-sina)=-2/sina
The denominator of 1-cosa / 1 + cosa under Radix is the same as that of 1-cosa under radix,
The denominator of 1 + cosa / 1-cosa under the root is the same as multiplying 1 + cosa under the root, and then adding
Note that sina is negative

Given that a is the fourth quadrant angle, the radical term 1-cosa / 1 + cosa + radical term 1 + cosa / 1-cosa is simplified

Dear landlord
First, multiply the numerator and denominator of the first radical by 1-cosa,
Since the square of sina + the square of cosa = 1, the first term is equal to (1-cosa) / Sina
Then multiply the denominator of the second root by 1 + cosa
Since the square of sina + the square of cosa = 1, the second term is equal to (1 + COSA) / Sina
Finally, add the first term and the second term to get 2 / Sina

Given that the final edge of the angle alpha passes through the point P (x, - radical 2) (x is not equal to 0), cos alpha = radical 3 / 6

Sin ^ 2A + cos ^ 2A = 1, if you know cosa, you can't find Sina yet? Notice which Sina you want according to point P, and then Tana comes out

If cos α + 2Sin α=- 5, then Tan α=______ .

From known
5sin（α+φ）=-
5 (where Tan φ = 1
2），
That is, sin (α + φ) = - 1,
So α + φ = 2K π - π
2，α=2kπ-π
2-φ（k∈Z），
So tan α = Tan (− π)
2−φ)=1
tanφ=2．
So the answer is: 2