We know how to draw the graphs of algebraic functions. Now using the same procedure we will learn how to draw the graphs of trigonometrical functions.
When we draw the graph of a trigonometrical function of the form y = f(x), we need to use the trigonometrical table for the values of the function f(x), for a set of values of x. Here x identifies as an angle. For all the values of f(x) are in the domain of definition of f(x).
Now we will plot a point O on the coordinate graph paper as an origin and through the origin O draw two mutually perpendicular lines XOX’ and YOY’. XOX’ and YOY’ are called x-axis and y-axis respectively.
Plot the angle x along x-axis and the trigonometrical function along y-axis. After plotting the tabulated values we will get a set of points on the graph paper. Now we will join the points. After joining the points we will get a continuous curve which is the required graph of the trigonometrical function.
We should take a sufficient number of values of x and y to
get an appropriate graphical presentation of a trigonometrical function.
In the following articles we have drawn the graphs of the functions sin x, cos x, tan x, cot x, cosec x and sec x.