mountain

sine

 

 

 http://www.mathopenref.com/sine.html

 

Sine (sin) function - Trigonometry

http://www.thefreedictionary.com/sine  https://www.mathsisfun.com/definitions/sine.html In a right triangle, the sine of an angle is the length of the opposite side divided by the length of the hypotenuse.

sin  x = O H

Try this Drag any vertex of the triangle and see how the sine of A and C are calculated.

The sine function, along with cosine and tangent, is one of the three most common trigonometric functions. In any right triangle, the sine of an angle x is the length of the opposite side (O) divided by the length of the hypotenuse (H). In a formula, it is written as 'sin' without the 'e':

Often remembered as "SOH" - meaning Sine is Opposite over Hypotenuse. See SOH CAH TOA.

 sin 

x

=

O

H

As an example, let's say we want to find the sine of angle C in the figure above (click 'reset' first). From the formula above we know that the sine of an angle is the opposite side divided by the hyupotenuse. The opposite side is AB and has a length of 15. The hypotenuse is AC with a length of 30. So we can write

 sin 

C

=

15

30

which comes out to 0.5. So we can say "The sine of 30° is 0.5 ", or

 sin 

C

=

0.5

Calculator

Use your calculator to find the sine of 30°. It should come out to 0.5 as above.
(If it doesn't - make sure the calculator is set to work in degrees and not radians).

 

sine

/sīn/

noun

• 1. the trigonometric function that is equal to the ratio of the side opposite a given angle (in a right triangle) to the hypotenuse.
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Definition of tangent

Definition of tangent

1. 1a :  meeting a curve or surface in a single point if a sufficiently small interval is considered <straight line tangent to a curve>b (1) :  having a common tangent line at a point <tangent curves> (2) :  having a common tangent plane at a point <tangent surfaces>