It is expressed by "cot+ angle", for example, the cotangent of 30 is expressed as cot30, and the cotangent of angle A is expressed as cota or ctgA, just like cotA. (Note: Not commonly used now) The abscissa of any point on the terminal edge of any angle except the vertex is divided by the non-zero ordinate of the point, and the vertex of the angle coincides with the origin of the plane rectangular coordinate system, while the starting edge of the angle coincides with the positive X axis. Simple understanding: the ratio of the adjacent side to the opposite side of any acute angle of a right triangle is called the cotangent of the acute angle.

Edit the cotangent properties in this paragraph.

1. Tangent is the reciprocal of 2. Monotonically decreasing by 3. Odd function 4. Lanchi R.

Edit the relevant formulas in this paragraph.

Harmony and harmonious relationship

1+cot^2α=csc^2α

Product relationship

cotα=cosα×cscα tanα cotα= 1

Relationship of quotient

cosα/sinα= Cotα= CSCα/secαCotx = 1/Tanx =[IE(IX)+IE(-IX)]/[E(IX)-E(-IX)]

Sum angle formula

cot(α+β)=(cotαcotβ- 1)/(cotα+cotβ)cot(α-β)=(cotαcotβ+ 1)/(cotβ-cotα