what is 'sin' in maths ?I'm in 9th grade .?

Answer 1

On the calc. you'll see SIN, COS, and TAN

Sin- Sine
Cos- Cosine
Tan- Tangent


All used for trigonometry.

Answer 2

Ever imagined how to measure height of a tree or mountain or a building at a given distance ? Make a triangle having sides, the height of the mountain, the distance of the bottom of the mountain from you and the distance of the top of the mountain from you. The make a small triangle with sides proportional to this big triangle( e.g. a/A = b/B = c/C). Notice that the two triangles have the same set of angles. Now, if a/A = c/C, then a/c = A/C. This a/c or A/C remains a constant for the angle BAC, whatever the size of the triangle. The two sides in the small triangle may be measured easily, and the distance of the mountain may also be measured approximately. Then the height of the mountain can be calculated from the equations of proportionality. The ratio, c/b = C/B is called sin of angle B or sine of angle B. The ratio a/c or A/C is called cosine of angle B or cos B. then thePythagoras theorem connects sine and cos of B, making sum of their squares one and the whole Trigonometry is created for service and use of the inquisitive man !

Answer 3

Sin is shorthand for Sine, a trigonometric function.

Without going into unnecessary detail, the sine of a right angled triangle can be calculated by dividing the length of the side opposite the angle by the length of the hypotenuse (which is the side opposite the right angle).

Similar Trigonometric functions are
cos - cosine (Adjacent/Hypotenuse)
tan - tangent (Opposite/Adjacent)
sec - secant (1/cos)
cosec - cosecant (1/sin)
cotan - cotangent (1/tan)

There are also hyperbolic versions of these functions, although I doubt you'd need those for 9th grade.

Answer 4

The trigonometric identites of Sine, Cosine, Tangent, Secant, Cosecant and Cot will be taught to you in 10th grade if you study in India. They apply to all right-angled triangles. Let ABC be a right-angled triangle where angle ABC = 90 degrees. Take theta to be any angle. Sin theta is equal to the opposite side divided by hypotenuse. Here, sin theta = AB/AC

Answer 5

In mathematics, the trigonometric functions are functions of an angle; they are important when studying triangles and modeling periodic phenomena, among many other applications. They are commonly defined as ratios of two sides of a right triangle containing the angle, and can equivalently be defined as the lengths of various line segments from a unit circle. More modern definitions express them as infinite series or as solutions of certain differential equations, allowing their extension to positive and negative values and even to complex numbers. All of these approaches will be presented below.

The study of trigonometric functions dates back to Babylonian times, and a considerable amount of fundamental work was done by Persian and Greek mathematicians.

In modern usage, there are six basic trigonometric functions, which are tabulated below along with equations relating them to one another. Especially in the case of the last four, these relations are often taken as the definitions of those functions, but one can define them equally well geometrically or by other means and then derive these relations. A few other functions were common historically (and appeared in the earliest tables), but are now seldom used, such as the versine (1 − cos θ) and the exsecant (sec θ − 1). Many more relations between these functions are listed in the article about trigonometric identities.

more:http://en.wikipedia.org/wiki/Sine

Answer 6

--------------------------------------------------------------------------------
Sin

Now let's have a look at sin in use. Below is a right-angle triangle with a 30° angle marked and two sides. Recall "sohcahtoa"! By definition, sin 30°



sin 30°
= opposite÷hypotenuse

= 4÷8

= 0·5



Sin 30° will always equal 0·5, when applied to right angle triangles..

Answer 7

im in 9th grade too and i know that. It is the part of the triangle that is opposite to the hypothenuse. It stands for something.
there is also sin, tan, and cos

Answer 8

it is a trigonometric ratio in a right triangle.the sine ratio of an angle called sin theta is the ratio of the side opposite the reference angle theta to the hypotenuse of the triangle

Answer 9

"sin" stands for sine . It has a lot to do with the three trigonometric functions, sine,cosine, and tangent. What level of math are you in?

Answer 10

Sine and cosines

In a right triangle, the ratio of the side opposite an acute angle to the hypoteneuse