Frequently the scale must be considerably coarser than this limit, in order to fit the entire plot onto a single sheet of graph paper. A scale finer than 1 div/mm would provide no additional plotting accuracy, since the data from the meter stick are only accurate to about 0.5 mm. For example, data from a meter stick (which has 1 mm graduations) should be plotted on a scale no finer than 1 division = 1 mm. Scales should be made no finer than the smallest increment on the measuring instrument from which data were obtained. Other choices (e.g., 0.3) make plotting and reading data very difficult. On coordinate paper, every 5 th and/or 10 th line is slightly heavier than other lines such a major division-line should always represent a decimal multiple of 1, 2, or 5 (e.g., 0, l, 2, 0.05, 20, 500, etc.). Choice of Scale Scales should be chosen in such a way that data are easy to plot and easy to read.

Axis Labels Each coordinate axis of a graph should be labeled with the word or symbol for the variable plotted along that axis and the units (in parentheses) in which the variable is plotted. Also, write your name and the date on the plot as well for convenient reference. Title Every graph should have a title that clearly states which variables appear on the plot. Use a sharp pencil (not a pen) to draw graphs, so that the inevitable mistakes may be corrected easily. Figure 1 Graph Paper Graphs that are intended to provide numerical information should always be drawn on squared or cross-section graph paper, 1 cm × 1 cm, with 10 subdivisions per cm.

Drawing two curves on one graph r