Tan 90 Degrees
Sin, Cos, Tan, Cot of an Angle
What is tan 90°?
Answer
tan 90°
is undefined
Angle in radians: 90° = π/2. The point of the angle is on the y-axis: (0, 1).
cos 90° = 0, and tan = sin / cos: you can't divide by zero, so the value doesn't exist.
tan 90° = sin 90° / cos 90° = 1 / 0
P(cos 90°, sin 90°) = (0, 1)
Line OP of 90° runs parallel to the line x = 1: they never meet, so tan 90° doesn't exist.
See Also
- Arcsin, Arccos, Arctan, Arccot - The angle from the value of its sine, cosine, tangent or cotangent: exact in degrees and π, with the check and the unit circle
- Square Root Calculator - Calculate the square root of any number
- Simplify Square Root Calculator - Write any square root in simplest radical form, step by step
- Geometry Formulas: Area, Volume, Perimeter - The formula for every standard shape, where it comes from, and worked examples
Tangent of nearby angles
FAQ
What is tan 90°?
tan 90° is undefined
Why does tan 90° not exist?
The point of 90° on the unit circle is (0, 1): cos 90° = 0, and tan = sin / cos would divide by zero. On the unit circle line OP runs parallel to the line x = 1 and never meets it.
Why does a calculator show −1.9952 for tan 90?
The calculator is in radian mode (RAD): it takes tan 90 as the tangent of 90 radians, tan 90 rad ≈ −1.9952. Switch it to degrees (DEG): tan 90° is undefined. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.
See Also
- Tan 80 Degrees: Tangent of 80° on the Unit Circle
- Tan 81 Degrees: Tangent of 81° on the Unit Circle
- Tan 82 Degrees: Tangent of 82° on the Unit Circle
- Tan 83 Degrees: Tangent of 83° on the Unit Circle
- Tan 84 Degrees: Tangent of 84° on the Unit Circle
- Tan 85 Degrees: Tangent of 85° on the Unit Circle
- Tan 86 Degrees: Tangent of 86° on the Unit Circle
- Tan 87 Degrees: Tangent of 87° on the Unit Circle
- Tan 88 Degrees: Tangent of 88° on the Unit Circle
- Tan 89 Degrees: Tangent of 89° on the Unit Circle
- Tan 97 Degrees: Tangent of 97° on the Unit Circle
- Tan 98 Degrees: Tangent of 98° on the Unit Circle
- Tan 100 Degrees: Tangent of 100° on the Unit Circle
- Tan 101 Degrees: Tangent of 101° on the Unit Circle
- Tan 105 Degrees: Tangent of 105° on the Unit Circle
- Tan 106 Degrees: Tangent of 106° on the Unit Circle
- Tan 108 Degrees: Tangent of 108° on the Unit Circle
- Tan 110 Degrees: Tangent of 110° on the Unit Circle
- Tan 120 Degrees: Tangent of 120° on the Unit Circle
- Tan 125 Degrees: Tangent of 125° on the Unit Circle
- Тангенс 90 градусов (tg 90°) на единичной окружности
- Tangente de 90 grados (tan 90°) en el círculo unitario
- Tangente de 90 graus (tg 90°) no ciclo trigonométrico