Trigonometric value

Tan(180°) = 0

Tangent — sine divided by cosine, equivalently opposite/adjacent in a right triangle; undefined where cos = 0.

How to derive tan(180°)

tan(180°)=0tan(180°) = 0

tan(180°) = sin(180°)/cos(180°) = 0 / (−1) = 0. The terminal side lies along the negative x-axis — a horizontal line through the origin has slope 0.

Unit-circle context

The angle 180° corresponds to π radians and sits on an axis on the unit circle.

Other trig values at 180°

Related tan values

Frequently asked

What is the exact value of tan(180°)?
The exact value is 0. Its decimal approximation is 0.
How do you derive tan(180°)?
tan(180°) = sin(180°)/cos(180°) = 0 / (−1) = 0. The terminal side lies along the negative x-axis — a horizontal line through the origin has slope 0.
What is 180° in radians?
180° equals π radians (multiply degrees by π/180).

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