noun
tangent
The ratio of an angle's sine to its cosine.
The tangent of a forty-five-degree angle is one.
Etymology
The trigonometric name arose from a geometric construction using a tangent line to a circle. That construction yields the ratio now defined as sine divided by cosine.
More examples
- She divided the sine by the cosine to calculate the tangent.
- The calculator displayed the tangent of the angle.
- The problem asked where the tangent function is undefined.
Forms
tangent · tangents
Similar words
- sine
- Sine is one trigonometric ratio; tangent equals sine divided by cosine where cosine is nonzero.
- cotangent
- Cotangent reverses the tangent ratio, giving cosine divided by sine where defined.