x^2 + exp(3 x) = 5, and press Enter. Click on the X after Solve for to change the variable name, if necessary, to whatever letter you wish to use. On the third line you can specify an interval in which to look for the solution. Finally, click on Go. X = ... (or whatever letter you are using for the variable) shows the value of the variable that the applet found (if it found one). F = ... shows the difference between left and right sides of your equation for that value of X. This should be close to 0. Note that numbers are sometimes written in "scientific notation", e.g. 1.234E-12 means 1.234 x 10-12. F' = ... shows the derivative of the difference of the two sides at that value of X.