In order to plot a graph choose a function and click it, or type it yourself into the input field and press 'Graph'. You can use only 'x' as the argument.
To graph the 'nth' root function of 'x' use the following entry: x^(1/n) - notice parentheses: without them you would get: (x^1)/n.
You can omit multiplication sign in expressions with a number: 5x, 10sin(x), 3(x-1); between parentheses:(x-7)(4+x); and between the variable and parentheses: x(x-3). The following expressions will cause an error: xsin(x), xx.
Consider the order of operations and if you are not sure of what comes first, use parentheses. For example: -x^2 and (-x)^2 - are not the same.
Keep in mind that the graph may not be drawn completely if 'y' approaches infinity quite rapidly because 'x' can't infinitely approach to asymptote due to computer limitations. That doesn't mean that the graph ends up and doesn't approach infinity.
Radians are used as the default in trigonometric functions.