Cosine cos is the abbreviation of cosine. Pronunciation: English [? ksa？ N], beauty [? ko？ Sa? n].

3. Tangent Tan is short for Tangent. Pronunciation: English [? t？ Ndnt], beauty [? t？ ndnt].

In a right triangle, sine is the ratio of the opposite side to the hypotenuse of a certain angle (non-right angle) of the right triangle, that is, the opposite side/hypotenuse; Cosine is the ratio of the adjacent side to the hypotenuse of a non-right angle; The tangent is the ratio of the opposite side to the adjacent side.

In any right triangle, the ratio of the opposite side to the adjacent side corresponding to θ is called the tangent of the angle θ. If θ is placed in a rectangular coordinate system, that is, tan θ = y/x. TanA= opposite side/adjacent side. Equivalent to the slope k of a straight line in a rectangular coordinate system.

Extended data

First, the functional relationship:

1, tangent tan is equal to the ratio of sine sin to cosine cos, and tanθ=sinθ/cosθ.

2. The product of sine and cosine is equal to 1, and sinθ×cosθ= 1.

3. The sum of the squares of sine and cosine is equal to 1, (sinθ)? +(cosθ)？ = 1。

Second, the application of sine function theorem in finding triangle area;

1、S△=c？ SinAsinB/2sin(A+B)(S△ is the area of triangle, with three angles ∠A∠B∠C and opposite sides ∠ A, B and C respectively).

2. s △ =1/2acsinb =1/2bcsina =1/2absinc (three angles ∠A∠B∠C, opposite sides are A, B and C respectively, see trigonometric function).

3. When the value of sin is between 180~360, a negative number will appear, which will be repeated above 360.