Cosθ

Definition

The cosine of an angle θ is the ratio of the length of the adjacent side to θ in a right triangle to the length of the hypotenuse.

Related terms

Sine (sinθ): The sine function represents vertical distances in a right triangle and is equal to opposite over hypotenuse.

Tangent (tanθ): The tangent function represents slopes and is equal to sine divided by cosine, or opposite over adjacent.

Secant (secθ): The secant function is equal to 1 divided by cosine, or hypotenuse over adjacent.