If Tan α = 2, cos (α + π) is equal to

If Tan α = 2, cos (α + π) is equal to

Cos (a + π) = - cosa. Given Tana = 2, angle a may be located in the first or third quadrant
Sin? A + cos? A = 1? Sina / cosa = 2
Therefore, cos (a + π) = - cosa = ±√ 5 / 5

If Tan A / 2 is known, cos A is equal to

cosa=2cos(a/2)^2-1=(1-tan(a/2)^2)/(1+tan(a/2)^2)

What is Tan (45 degrees + 30 degrees),

The formula of two angles and tangent: Tan (α + β) = (Tan α + Tan β) / (1-tan α Tan β)
tan(45°+30°)
=(tan45°+tan30°)/(1-tan45°·tan30°)
=(1+√3/3)/(1-√3/3)
=2+√3
=tan75°

How much is Tan (45 + 30)

Tan (45 + 30) = (tan45 + tan30) / (1-tan45tan30) = [1 + (radical 3) / 3] / [1 - (radical 3) / 3]

How many degrees is Tan equal to minus 2 / 3?

tan(-33.7°)=-2/3
Or tan 146.3 ° = - 2 / 3

What is tan-2 equal to

two point one eight five zero three nine eight six

If sin α = 4 If α is the second quadrant angle, the value of Tan α is () A. -4 Three B. 3 Four C.   + − Three Four D.   + − Four Three

If sin α = 4
If α is the second quadrant angle, then cos α=-
1−sin2α=-3
5，
So tan α = sin α
cosα=4
Five
−3
5=-4
3．
Therefore, a

If Tan α = 2, cos (2 α + π) is equal to? And sin (π - α) cos (- α) =?

tanα=2 ,secα=±√5 ,cosα=±√5/5 ,sinα=±2√5/5
cos（2α+π）=-cos2α=1-2cos^2α=3/5
sin（π-α）cos（-α）=sinαcosα=±2/5

Why is (1-cos α) / sin α equal to sin α / (1 + cos α) equal to tan (α / 2)

Why is (1-cos α) / sin α equal to sin α / (1 + cos α) equal to tan (α / 2)
(1-cosα)/sinα=(1-cosα)(1+cosα)/[sinα(1+cosα)]=(1-cos²α)/[sinα(1+cosα)]
=sin²α/[sinα(1+cosα)]=sinα/(1+cosα)
=2sin(α/2)cos(α/2)/[2cos²(α/2)]=sin(α/2)/cos(α/2)=tan(α/2)
In this paper, the angle doubling formula is used: Cos2 α = 2cos 2 α - 1; 1 + Cos2 α = 2cos 2 α

Sin 3π/2= ,cosπ= ,tanπ=

(1)=-1
(2)=1
(3)=0