By pressing Solve f(x) = 0 the Graphing Calculator finds the x-intercepts (roots (zeros)) of the function on the specified bounded interval and displays them in a new window.
In most cases the Online Graphing Calculator finds all the roots (zeros) on the interval very efficiently. In other cases, some roots (zeros) (or solution of (f(x) = 0) are not detected on the first try. This might happen when the graph of the function touches the x-axis without crossing it, for example, (x - 0.123)2 or sin(x)2.
Fortunately, the Online Graphing Calculator is able to handle these cases very accurately. Press the Try again button to find other roots (zeros) that might have been missed. These two cases are handled separately for the sake of saving time for finding roots (zeros) for most functions that do not need a second try, and especially, when the domain interval is very large.
However there are trivial cases that you will find excess "roots (zeros)" appear because of round off error. This happens when the graph of the function is very close to the x-axis on a sub-interval. For example, the graph of x10 is very close to the x-axis on a sub-interval about 0 which produces "unwanted roots (zeros)" especially when you press Try again.
It is always helpful to look at the graphs when finding the roots (zeros) of functions.