
Trigonometry 



Trigonometric
Functions and Inverse Trigonometric Functions 
Trigonometric
functions graphs and relations 
The
sine function and the cosine function graphs and relations 





Trigonometric
functions and inverse trigonometric functions or
arcfunctions 
Trigonometric
functions graphs and relations 
Trigonometric
(cyclometric) functions are defined as the ratios of the sides of a right
triangle containing the angle equal to the argument of the
function in radians.

Or
more generally, for real arguments, trigonometric
functions are defined in terms of the coordinates of the terminal
point Q of
the arc
(or angle) of the unit circle with the initial point at P(1,
0). 



sin^{2}x
+ cos^{2}x
= 1 



 The
sine function
y
= sin x
is the ycoordinate
of the terminal point of the arc x
of the unit circle. 
The
graph of the sine function is the sine curve or sinusoid. 
In
a rightangled triangle the
sine function is equal to the ratio of the length of the side
opposite the given angle to the length of the hypotenuse. 



 The
cosine function
y
= cos x
is the xcoordinate
of the terminal point of the arc x
of the unit circle. 
The
graph of the cosine function is the cosine curve or cosinusoid. 
In
a rightangled triangle the cosine function is equal to the
ratio of the length of the side adjacent the given angle to the
length of the hypotenuse. 










Trigonometry
contents B 



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