# Sine of an angle

## Definitions

• Webster's Revised Unabridged Dictionary
• Sine of an angle in a circle whose radius is unity, the sine of the arc that measures the angle; in a right-angled triangle, the side opposite the given angle divided by the hypotenuse. See Trigonometrical function, under Function.
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## Usage

### In literature:

Now you know what the versed sine of an angle is, and are able to observe in Fig.
"Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886" by Various
Then also the Sine of the angle DAE is to the Sine of NAF as BC is to AN.
"Treatise on Light" by Christiaan Huygens
An astronomical term denoting the angle whose sine is equal to the eccentricity of an orbit.
"The Sailor's Word-Book" by William Henry Smyth
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### In science:

In (hvp i, Θ) space, these GCs trace almost perfectly (with a dispersion of only ∼100 km s−1 ) a sine curve with peak and trough at the position angles of the ma jor axis and an amplitude ΩR = +300 km s−1 .
Dynamics of the Globular Cluster System Associated with M49 (NGC4472): Cluster Orbital Properties and the Distribution of Dark Matter
Then one can determine the cosine and sine of an interior angle by deriving the unit tangent vectors at the vertices of interest.
The Hanle Effect as a Diagnostic of Magnetic Fields in Stellar Envelopes IV. Application to Polarized P Cygni Wind Lines
For D ≡ 1 (mod 4) it is also an algebraic integer when a and b as special values of (co)sine at rational angles. Z. (Note e.g. that 1 Observation (Quadratic Irrationalities). i) Let x be a quadratic integer such that |x| < 2 and |x| < 2.
When is the (co)sine of a rational angle equal to a rational number?
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