Roots[lhs == rhs, var] yields a disjunction of equations which represent the roots of a polynomial equation.

SubscriptBox[x, y] is the low-level box representation for x_y in notebook expressions.

SyntaxForm is an option for InterpretationBox and TagBox objects that specifies the precedence level to use when the InterpretationBox or TagBox is considered as an operator.

ToUpperCase[string] yields a string in which all letters have been converted to uppercase.

Unprotect[s_1, s_2, ...] removes the attribute Protected for the symbols s_i. Unprotect["form_1", "form_2", ...] unprotects all symbols whose names textually match any of the ...

Write[channel, expr_1, expr_2, ...] writes the expressions expr_i in sequence, followed by a newline, to the specified output channel.

$MessageList is a global variable that gives a list of the names of messages generated during the evaluation of the current input line.

Converting power series to normal expressions. Power series in Mathematica are represented in a special internal form, which keeps track of such attributes as their expansion ...

Differentiating a known function gives an explicit result. Differentiating an unknown function f gives a result in terms of f'. Mathematica applies the chain rule for ...

When you see a two-dimensional expression on the screen, you can edit it much as you would edit text. You can for example place your cursor somewhere and start typing. Or you ...