Excel's Formula - sisman

Chapter 17: Charting Techniques 455
Plotting a circle
You can create an XY chart that draws a perfect circle. To do so, you need two ranges: one for
the x values and another for the y values. The number of data points in the series determines the
smoothness of the circle. Or you can simply select the Smoothed Line option in the Format Data
Series dialog box (Line Style tab) for the data series.
Figure 17-17 shows a chart that uses 13 points to create a circle. If you work in degrees, generate a
series of values such as the ones shown in column A. The series starts with 0 and increases in
30-degree increments. If you work in radians (column B), the first series starts with 0 and increments
by Π/6.
Figure 17-17: Creating a circle using an XY chart.
The ranges used in the chart appear in columns D and E. If you work in degrees, the formula in
cell D2 is
=SIN(RADIANS(A2))
The formula in cell E2 is
=COS(RADIANS(A2))