Note on Cosine Rule

Introduction of learning cosine rule:-

In this section let me help you on cosine rule. Before i go more deeper on this let me help you on what is all about cosine?

What is a cosine?

Cosine , abbrevated as cos, is one of the trigonometric functions which are used to relate angles with sides in a right triangle .Cosine is a periodic function with period 180o .It has maximum value at multiples of 360o and minimum value at multiples of 90o angles.

Defnition of cosine :

Cosine of an angle [theta] in a right triangle is definrd as ratio of the length of side adjacent to angle [theta] to the

hypotenuse of triangle. This will also help you on cumulative frequency

cosine

In the above right triangle:

["cos ] is difined as ratio of length of adjacent side 'a' of angle theta to length of hypotenuse of

triangle 'b' . SO cos [theta] = a / b.