If sin α = 3 / 5 (π / 2 ＜ α (π)), what is cos (α - π / 3) equal to

If sin α = 3 / 5 (π / 2 ＜ α (π)), what is cos (α - π / 3) equal to

sinα=3/5 (π/2

Cos (a - (3 Π - 2)) = 1|5, a is the third quadrant angle, find cos a

cos(a-(3∏\2))=cos((3∏\2)-a)=-cos(∏\2-a)=-sina=1/5
So Sina = - 1 / 5
Because a is the third quadrant angle
So cos a = - √ (1-1 / 25) = - 2 / 5 √ 6

If cos α = - 3 / 5 and α is the third quadrant angle, find cos (α + 2 / 3 π) I have to go 4 / 5, right? Talk about the process and see what I think, right

Cos (α + 2 / 3 π) is this a three-thirds school?
cos(α+3π/2)=cosαcos(3π/2)-sinαsin(3π/2)=-sinα=√[1-(cosα)^2]=√[1-(-3/5)^2]=4/5

Cos (α - 3 π / 2) = 1 / 5, sin α * cot α α is the third quadrant angle

cos(α-3π/2)=-sinα=1/5
sinα=-1/5
sin²α+cos²α=1
In the third quadrant, cos α < 0
So cos α = - 2 √ 6 / 5
The original formula = sin α * cos α / sin α = cos α = - 2 √ 6 / 5

Sin α = - 3 / 5, α is the third quadrant angle, cos α value is (c) A. - 1 B. √ 3 / 2 Sin α = - 3 / 5, α is the third quadrant angle, cos α value is (c) A. - 1 B. √ 3 / 2 C. - 4 / 5 D.3 / 4, the more detailed the better,

The answer is C
[analysis] α is the third quadrant angle, cos α < 0
Sin α squared + cos α squared = 1
The square of cos α is 16 / 25
Because cos α is less than 0
Therefore, cos α = - 4 / 5

Let α make the third quadrant angle, Tan (π - α) = - 5 / 12, then cos (3 π / 2 - α)=

Let α make the third quadrant angle, Tan (π - α) = - 5 / 12, then cos (3 π / 2 - α)=
Tan (π - α) = - Tan α = - 5 / 12, ν Tan α = 5 / 12; then α = π + arctan (5 / 12)
Therefore, cos (3 π / 2 - α) = - sin α = - sin [π + arctan (5 / 12)] = sin [arctan (5 / 12) = 5 / √ 119 = 0.4583

Cos (Pie / 4 + x) = 1 / 3 sin2x=

Sin(π/4+x)=1/3
Radical 2 / 2cosx + Radix 2 / 2sinx = 1 / 3
Square on both sides, 1 / 2 + cosxsinx = 1 / 9
cosxsinx=-7/18
sin2x=-7/9

What is cos in mathematics?

Cosine function, sine is sin, tangent is tan, cot is cot

Mathematics! Known sin α + sin β = 1 - √ 3 / 2, cos α + cos β = 1 / 2, if α - β ∈ (0, π), find the value of α - β Given that sin α + sin β = 1 - √ 3 / 2, cos α + cos β = 1 / 2, if α - β ∈ (0, π), calculate the value of α - β

Sin α + sin β = 1 - √ 3 / 2, the square is sin ^ 2A + 2sinasinb + sin ^ 2B = 7 / 4 - √ 3cos α + cos β = 1 / 2, the square is cos ^ 2A + 2cosacosb + cos ^ 2B = 1 / 4, add 2 + 2 (cosacosb + sinasinb) = 2 - √ 32cos (a-b) = - √ 3cos (a-b) = - √ 3 / 2 α - β ∈ (0, π), α - β = 5

It is known that 0 ＜ a ＜ 2 ＜ β ＜ π, cos (β - 4 π) = 1 / 3, sin (a + β) = 5 / 4 1, find the value of sin2 β 2, find the value of COS (a + 4 parts π)

A:
Zero