Tan 179 Degrees

Sin, Cos, Tan, Cot of an Angle
Function
Angle (°)

What is tan 179°?

Answer

tan 179° ≈
−0.0175

Angle in radians: 179° = 179π/180. The point of the angle is in quadrant II, where tangent is negative.

≈ — rounded to 4 decimal places. tan 179° can't be written with square roots: 179° is not a multiple of 3°.

tan 179° = tan(180° − 1°) = −tan 1° ≈ −0.0175

tan 179° = sin 179° / cos 179° ≈ −0.0175

xyOP

P(cos 179°, sin 179°) ≈ (−0.9998, 0.0175)

T(1, tan 179°) ≈ (1, −0.0175) — where line OP meets the line x = 1, on the extension of the ray beyond O (dashed).

All four functions of 179°
FunctionExact valueDecimal
sin 179°—≈ 0.0175
cos 179°—≈ −0.9998
tan 179°—≈ −0.0175
cot 179°—≈ −57.2900

Reference angle: tan 1° ≈ 0.0175

See Also

Recalculate with different values ↑

Tangent of nearby angles

Angletan
165°√3 − 2
167°≈ −0.2309
175°≈ −0.0875
179°≈ −0.0175
180°0
195°2 − √3
198°√(25 − 10√5)/5

FAQ

What is tan 179°?

tan 179° ≈ −0.0175

Why does tan 179° have no exact value?

A trigonometric value of a whole number of degrees can be written with square roots only when the angle is a multiple of 3°. 179° is not, so no such exact form exists; the value is used as a decimal: tan 179° ≈ −0.0175.

Why does a calculator show −0.0709 for tan 179?

The calculator is in radian mode (RAD): it takes tan 179 as the tangent of 179 radians, tan 179 rad ≈ −0.0709. Switch it to degrees (DEG): tan 179° ≈ −0.0175. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also