Tangent Calculator
Calculate tan of an angle in degrees; undefined angles are rejected.
Formula
tan(θ) = sin(θ)/cos(θ); reduce θ modulo 180° before calculation
Tangent ≈ tan(((45)-180×floor(((45)+90)÷180))×pi÷180)
How to use
- Enter an angle in degrees.
- Use the scientific calculator for radian expressions.
- Read the tangent or the undefined-angle message.
Examples
- tan(45°) = 1; tan(−45°) = −1.
Frequently asked questions
What is tan 45°?
It equals 1 because opposite and adjacent legs are equal.
Why is tan 90° undefined?
Cosine is zero at 90° plus integer multiples of 180°, so the ratio would divide by zero.
Why are values near 90° large?
Cosine approaches zero. Small angle changes can then cause large changes in tangent.
Sources
Updated: