Trigonometric functions - I

There are six basic trigonometric functions.

1. sin x

2. cos x

3. tan x

4. cosec x

5. sec x

6. cot x

To draw the graph of these functions we will consider a circle of unit radius and observe the behaviour of these trigonometrical function as point P moves anticlockwise in the below figure.

1. f(x) = sinx

since, sin x = a

Observe the variations in 'a' in the above figure

From above figure, it can be concluded that 

when x = 0, sin x = 0

when , sin x = 1

and after every interval of   , the 'sin x' repeats its values

i.e. f(x) = sin x is a "periodic function" of period 

observe the variation of 'a', the graph of 'sin x' is given below

Domain = R

Range = [-1,1]

2. f(x) = cos x

since, cos x = b

observe the variation of 'b'

i.e. f(x) = cos x is a "periodic function" of period 

Domain = R

Range = [-1,1]

3. f(x) = tan x

since tan x = a/b

observe the variation in 'a/b'

Range = R

It repeats its value after every interval of 

i.e. f(x) = tan x is a "periodic function" of period