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    Cos 215 Degrees

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

    What is cos 215°?

    Answer

    cos 215° ≈
    −0.8192

    Angle in radians: 215° = 43π/36. The point of the angle is in quadrant III, where cosine is negative.

    ≈ — rounded to 4 decimal places. cos 215° can't be written with square roots: 215° is not a multiple of 3°.

    cos 215° = cos(180° + 35°) = −cos 35° ≈ −0.8192

    P(cos 215°, sin 215°) ≈ (−0.8192, −0.5736)

    xyOP

    P(cos 215°, sin 215°) ≈ (−0.8192, −0.5736)

    Highlighted: the projection on the x-axis — cosine, x ≈ −0.8192.

    All four functions of 215°
    FunctionExact valueDecimal
    sin 215°—≈ −0.5736
    cos 215°—≈ −0.8192
    tan 215°—≈ 0.7002
    cot 215°—≈ 1.4281

    Reference angle: cos 35° ≈ 0.8192

    See Also

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    https://calculat.io/en/number/trigonometry/cos--215Copy
    <a href="https://calculat.io/en/number/trigonometry/cos--215">Cos 215 Degrees: Cosine of 215° on the Unit Circle</a>Copy
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    Cos 215 Degrees: Cosine of 215° on the Unit Circle. cos 215° ≈ −0.8192. The cosine is the x-coordinate of the point at 215° on the unit circle; 215° reduces to 35°.
    https://calculat.io/en/number/trigonometry/cos--215/generated.jpgCopy

    Cosine of nearby angles

    Anglecos
    200°≈ −0.9397
    210°−√3/2
    211°≈ −0.8572
    215°≈ −0.8192
    216°−(√5 + 1)/4
    225°−√2/2
    227°≈ −0.6820
    Recalculate with different values ↑

    FAQ

    What is cos 215°?

    cos 215° ≈ −0.8192

    Why does cos 215° 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°. 215° is not, so no such exact form exists; the value is used as a decimal: cos 215° ≈ −0.8192.

    Why does a calculator show 0.1978 for cos 215?

    The calculator is in radian mode (RAD): it takes cos 215 as the cosine of 215 radians, cos 215 rad ≈ 0.1978. Switch it to degrees (DEG): cos 215° ≈ −0.8192. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

    See Also