The figure shows the idea of constructing
the function; y = a sin x + b cos x
The angle OAP is always 90 degrees. When the figure OAP rotates arround the origin, the y-coordinate of point P represents the function.
The applet shows the graph of
y = a sin x + b cos x
The initial value of a and b are 1 and 0.5 respectively.
To draw the graph, press "Draw" button.