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    Cos 28 Degrees

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

    What is cos 28°?

    Answer

    cos 28° ≈
    0.8829

    Angle in radians: 28° = 7π/45. The point of the angle is in quadrant I, where cosine is positive.

    ≈ — rounded to 4 decimal places. cos 28° can't be written with square roots: 28° is not a multiple of 3°.

    P(cos 28°, sin 28°) ≈ (0.8829, 0.4695)

    xyOP

    P(cos 28°, sin 28°) ≈ (0.8829, 0.4695)

    Highlighted: the projection on the x-axis — cosine, x ≈ 0.8829.

    All four functions of 28°
    FunctionExact valueDecimal
    sin 28°—≈ 0.4695
    cos 28°—≈ 0.8829
    tan 28°—≈ 0.5317
    cot 28°—≈ 1.8807

    See Also

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    https://calculat.io/en/number/trigonometry/cos--28Copy
    <a href="https://calculat.io/en/number/trigonometry/cos--28">Cos 28 Degrees: Cosine of 28° on the Unit Circle</a>Copy
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    Cos 28 Degrees: Cosine of 28° on the Unit Circle. cos 28° ≈ 0.8829. The cosine is the x-coordinate of the point at 28° on the unit circle.
    https://calculat.io/en/number/trigonometry/cos--28/generated.jpgCopy

    Cosine of nearby angles

    Anglecos
    25°≈ 0.9063
    26°≈ 0.8988
    27°≈ 0.8910
    28°≈ 0.8829
    29°≈ 0.8746
    30°√3/2
    31°≈ 0.8572
    Recalculate with different values ↑

    FAQ

    What is cos 28°?

    cos 28° ≈ 0.8829

    Why does cos 28° 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°. 28° is not, so no such exact form exists; the value is used as a decimal: cos 28° ≈ 0.8829.

    Why does a calculator show −0.9626 for cos 28?

    The calculator is in radian mode (RAD): it takes cos 28 as the cosine of 28 radians, cos 28 rad ≈ −0.9626. Switch it to degrees (DEG): cos 28° ≈ 0.8829. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

    See Also