Draw and label the horizontal and vertical axes of the graph. Use a ruler to draw the axes on the graph paper. The horizontal x-axis represents the argument of the cosine function and can be represented by x. The vertical y-axis represents the cosine function and can be represented by y, where y = cosine (x).
Mark and label the intervals on the x- and y-axes. Start the x-axis at 0 degrees and end at 360 degrees, using intervals of 10 degrees. Start the y-axis at -1 and end at +1. Use intervals of 0.2 for the y-axis.
Write a selection of the integers ranging from 0 to 360 on a piece of paper. Include 0, 180, and 360 in your selection. The more integers you use, the more accurate your graph will be.
Use the cosine function on your calculator to find the cosine of each integer and write it alongside the integer. Each pair of numbers (integer; cosine of integer) is a data point for your graph. The integer is the x-coordinate of the point, while the cosine of the integer is the y-coordinate of the point (x; y). For example, the cosine of the integer 100 is -0.17 = cosine (100). The resulting data point is (100; -0.17) = (x; y).
Plot all the (x, y) data points on the graph paper. Use a pencil dot to represent each point.
Draw a line through the data points. Avoid drawing the line from dot to dot. Rather, use a sweeping motion of the pencil across the paper so that the curved line passes smoothly through all the data points.