# Trig terms

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definitions & notes only words
1. arccosine
the inverse function of the cosine
The inverse functions are called the arcsine, arccosine, and arctangent, respectively.
2. arctangent
the inverse function of the tangent
The inverse functions are called the arcsine, arccosine, and arctangent, respectively.
3. cotangent
ratio of the adjacent to the opposite side of a right-angled triangle
The reciprocals of these functions are named the cosecant (csc or cosec), secant (sec) and cotangent (cot), respectively.
4. arcsine
the inverse function of the sine
The inverse functions are called the arcsine, arccosine, and arctangent, respectively.
5. trigonometric function
function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle
These ratios are given by the following trigonometric functions of the known angle A, where a, b and c refer to the lengths of the sides in the accompanying figure:

* The sine function (sin), defined as the ratio of the side opposite the angle to the hypotenuse.
6. trigonometric
of or relating to or according to the principles of trigonometry
These ratios are given by the following trigonometric functions of the known angle A, where a, b and c refer to the lengths of the sides in the accompanying figure:

* The sine function (sin), defined as the ratio of the side opposite the angle to the hypotenuse.
the unit of plane angle adopted under the Systeme International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees)
Graphing process of y = csc(x) using a unit circle.
 Extending the definitions
Graphs of the functions sin(x) and cos(x), where the angle x is measured in radians.
8. cosecant
ratio of the hypotenuse to the opposite side of a right-angled triangle
The reciprocals of these functions are named the cosecant (csc or cosec), secant (sec) and cotangent (cot), respectively.
9. inverse function
a function obtained by expressing the dependent variable of one function as the independent variable of another; f and g are inverse functions if f(x)=y and g(y)=x
The inverse functions are called the arcsine, arccosine, and arctangent, respectively.
10. cosine
ratio of the adjacent side to the hypotenuse of a right-angled triangle
* The cosine function (cos), defined as the ratio of the adjacent leg to the hypotenuse.
11. secant
a straight line that intersects a curve at two or more points
The reciprocals of these functions are named the cosecant (csc or cosec), secant (sec) and cotangent (cot), respectively.
12. function
what something is used for
These ratios are given by the following trigonometric functions of the known angle A, where a, b and c refer to the lengths of the sides in the accompanying figure:

* The sine function (sin), defined as the ratio of the side opposite the angle to the hypotenuse.
13. sine
ratio of the length of the side opposite the given angle to the length of the hypotenuse of a right-angled triangle
These ratios are given by the following trigonometric functions of the known angle A, where a, b and c refer to the lengths of the sides in the accompanying figure:

* The sine function (sin), defined as the ratio of the side opposite the angle to the hypotenuse.
14. tangent
a line that touches a curve but does not intersect it
Many people find it easy to remember what sides of the right triangle are equal to sine, cosine, or tangent, by memorizing the word SOH-CAH-TOA (see below under Mnemonics).
15. angle
the space between two lines or planes that intersect
If one angle of a triangle is 90 degrees and one of the other angles is known, the third is thereby fixed, because the three angles of any triangle add up to 180 degrees.