Trigonometry

Contents of the Presentation History of Trigonometry

Where it is used

Basic concepts in trigonometry

Trigonometric table

Trigonometric identities

History of Trigonometry The complex origins of trigonometry are embedded in

the history of the simple word "sine," a mistranslation of an Arabic transliteration of a Sanskrit mathematical term. The complex etymology of "sine" reveals trigonometry's roots in Babylonian, Greek, Hellenistic, Indian, and Arabic mathematics and astronomy.

Although trigonometry now is usually taught beginning with plane triangles, its origins lie in the world of astronomy and spherical triangles. Before the sixteenth century, astronomy was based on the notion that the earth stood at the centre of a series of nested spheres. To calculate the positions of stars or planets, one needed to use concepts we now refer to as trigonometry.

Where it is used in daily life Trigonometry is commonly used in finding the

height of towers and mountains.

It is used in navigation to find the distance of the shore from a point in the sea.

It is used in finding the distance between celestial bodies.

It is used in oceanography in calculating the height of tides in oceans.

Basic concepts in Trigonometry Right Angle Triangle :

Right angle triangle is a triangle in which one of its interior angle is 90 degree. The opposite side of the right angle triangle is hypothesis and the other two sides are adjacent and opposite. Basic sin,cos and tan functions are as follows,

Name Ratio NotationSine Opposite/hypotenuse Sin(0)

Cosine Adjacent/hypotenuse Cos(0)

Tangent Opposite/adjacent Tan(0)

Cosecant(1/Sine) Hypotenuse/Opposite Cosec(0) or csc(0)

Secant(1/Cosine) Hypotenuse/adjacent Sec(0)

Contagent(1/Tangent) Adjacent/opposite Cot(0)

Basic concepts of Trigonometry

Pythagoras Theorem: Pythagoras theorem is used to find the sides of

The right angle. Pythagoras theorem is,

(Hypotenuse)2=(Adjacent)2 + (Opposite)2

Triangle Identities: Triangle identities are the function. There are

some identities which are true for right angle triangles and some are true for all triangles.

Trigonometric table

Created byAshwin Rao