cosine

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noun co·sine \ ˈkō-ˌsīn \
Updated on: 11 Sep 2017

Definition of cosine

1 :a trigonometric function that for an acute angle is the ratio between the leg adjacent to the angle when it is considered part of a right triangle and the hypotenuse
2 :a trigonometric function cos θ that for all real numbers θ is given by the sum of a series of which the first term is 1 and succeeding terms alternate in sign with the kth term consisting of a fraction whose numerator is θ raised to the exponent 2(k - 1) and whose denominator is the factorial of 2(k - 1) and that is exactly equal to the cosine of an angle of measure θ in radians

Recent Examples of cosine from the Web

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Origin and Etymology of cosine

New Latin cosinus, from co- + Medieval Latin sinus sine


COSINE Defined for English Language Learners

cosine

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noun

Definition of cosine for English Language Learners

  • geometry : the ratio between the long side (called the hypotenuse) and the side that is next to an acute angle in a right triangle


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