image method in addition to a number other than a little trouble, you can better study and the nature of the correlation function of the image, you can get more information. To solve the equation

study lgx + x2 = 0, we can know what we seek is the solution function y = lgx and y =- x2 intersection of the horizontal image, and that the two images is greater than zero only in the small x 1 was possible in the intersection. We only have a rectangular coordinate system to make these two functions of the image then the results also clear up.

shown in Figure 1, the A2, A3, A4 cells, respectively, enter "0.01", "0.02", "0.03", then select the three cells down drag the fill handle to A151 cells lattice. In cell B2 enter the formula "= LOG (A2)", in cell C2 enter the formula "=- (A2 ^ 2)". Select the two cells, drag the fill handle to copy the formula down to the C151 cells.

Figure 1

Now select A1: C151 cell, click the function area "insert" tab "Charts" Functional Group "plot" button in the pop-up menu, click on the "Scatter with smooth lines" button, such as Figure 2.
Figure 2

soon, it will appear in the current worksheet function we want images, shown in Figure 3. Find the intersection, do not you can solve it?
Figure 3

more convenient to see the result, we can make more precise vertical grid lines show more. Just select the chart, then click on the emerging functional area "Chart Tools" under the "Layout" tab of the "axis" functional group "grid line" button in the pop-up menu click on the "main vertical grid lines ¡ú secondary grid line "command on it.

Well, if you have encountered a similar mathematical problem, then it may give it to Excel, and let the computer help we solve those complicated calculations, Oh on, we just results!