Square relation: sin2alpha+cos2alpha =11+tan2alpha = sec2alpha1+cot2alpha = csc2alpha product relation: sinα = tanα× cosα cosα = cotα× sinα tanα. C α = Tan α× CSC α CSC α = Secα× Cotα reciprocal relation: Tan α Cot α =1Sin α CSC α =1Cos α Sec α =1quotient relation: Sinα/Cosα = Tan α = Secα/CSC α Cosα. Sinα = Cotα = CSC α/Secα In the right triangle ABC, the sine value of angle A is equal to the opposite side of angle A, the cosine value is equal to the adjacent side of angle A, and the tangent of the hypotenuse is equal to the opposite side. [1] The trigonometric function of the sum and difference of two angles in the trigonometric function constant deformation formula: cos (α+β) = cos α, cos β-sin α, sin β cos (α-β) = cos α, cos β+sin α, sin β sin (α β) = sin α, cos β, cos α. The trigonometric function of the trigonometric sum of (1-tan α tan β) tan (α β) = (tan α tan β)/(1+tan α tan β): sin(α+β+γ). = sinαcosβcosγ+cosαsinβcosγ+cosαcosβsinγ-sinαsinβsinγcos(α+β+γ)= cosαcosαcosβsinγ-sinαcosβsinαsinβcosγ=(tanα+tanβ+tanγ-tanαtanβtanγ)/( 1 -tan α tan β tan γ-tan γ tan α) auxiliary angle formula: asinα+bcosα = (a+Bt ant = a/B. Double angle formula: sin (2α) = 2sinα cos α = 2/(tan α+cot α) cos (2α) = cos (α)-sin (α. Triple angle formula: sin (3α) = 3sinα-4sin (α) = 4sinα sin (60+α) sin (60-α) cos (3α) = 4cosα = 4cosα cos (60+α) cos (60-. Half-angle formula: sin (α/2) = √ ((kloc-0/-cos α)/2) cos (α/2) = √ ((kloc-0/+cos α)/2) tan (α/2) = √ ((65438) sin α power drop. Kloc-0/+cos(2α))/2 = Covers(2α product sum and difference formula: sin α cos β = (1/2) [sin (α+β)+sin (α-β)] cos α sin β = (1/2) [ [COS(α+β)-COS(α-β)] and difference product formula: sin α+sin β = 2 sin [(α+β)/2] COS [(α-β)/2]