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    TAN

    Math & Trig

    Returns the tangent of an angle specified in radians.

    Translations
    EnglishTAN
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    FinnishTAN
    Syntax
    TAN(number)

    Arguments

    • numberThe angle in radians
    Examples
    =TAN(0)
    0

    Tangent of 0 is 0

    =TAN(RADIANS(45))
    1

    Tangent of 45 degrees is 1

    =TAN(PI()/4)
    1

    PI/4 radians = 45 degrees, tangent is 1

    Tips & Best Practices
    • •TAN = SIN / COS
    • •Undefined at 90 degrees (PI/2 radians)
    • •Use RADIANS() to convert from degrees first
    Common Mistakes
    • •Passing an angle in degrees directly to TAN without converting it first - TAN expects radians, so TAN(90) doesn't give the tangent of 90 degrees, and RADIANS(90) needs to be used instead
    • •Applying TAN to an angle where tangent is mathematically undefined (like 90 degrees), which doesn't raise a clean error but instead returns an extremely large number due to floating-point limitations
    • •Confusing TAN with ATAN - TAN takes an angle and returns a ratio, while ATAN takes a ratio and returns an angle, and using the wrong one inverts the intended calculation
    Related Functions
    SINCalculates the sine of an angle, related to TAN through the identity tan(x) = sin(x)/cos(x).
    ATANPerforms the inverse operation - takes a tangent value and returns the corresponding angle in radians.
    RADIANSConverts a degree value into radians, the unit TAN expects for its angle argument.
    Frequently Asked Questions

    Why doesn't TAN(90) give an error even though tangent is undefined at 90 degrees?

    TAN(90) uses 90 radians, not degrees, so it's not actually hitting the undefined point. Even TAN(RADIANS(90)) returns an extremely large number rather than a clean error, due to floating-point rounding near the true undefined point.

    What's the difference between TAN and ATAN?

    TAN takes an angle (in radians) and returns a ratio. ATAN does the reverse - it takes that ratio and returns the corresponding angle.

    Why do I need RADIANS before using TAN?

    TAN expects its input in radians, not degrees. If your angle is in degrees, wrap it in RADIANS first, like TAN(RADIANS(45)).

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