Interpolation[{f_1, f_2, ...}] constructs an interpolation of the function values f_i, assumed to correspond to x values 1, 2, ... . Interpolation[{{x_1, f_1}, {x_2, f_2}, ...

f' represents the derivative of a function f of one argument. Derivative[n_1, n_2, ...][f] is the general form, representing a function obtained from f by differentiating n_1 ...

ExistsRealQ[ineqs, {x_1, x_2, ...}] tests whether there exist real values of the x_i for which the inequalities and equations ineqs are satisfied.

ForAllRealQ[ineqs, {x_1, x_2, ...}] tests whether for all real values of the x_i the inequalities and equations ineqs are satisfied.

ImpliesRealQ[ineqs_1, ineqs_2] tests whether the inequalities and equations ineqs_1 imply the ineqs_2 for all real values of all variables.

DiracComb[x] represents the Dirac comb function giving a delta function at every integer point. DiracComb[x_1, x_2, ...] represents the multidimensional Dirac comb function.

SetPrecision[expr, p] yields a version of expr in which all numbers have been set to have precision p.

HeavisideTheta[x] represents the Heaviside theta function \[Theta](x), equal to 0 for x < 0 and 1 for x > 0. HeavisideTheta[x_1, x_2, ...] represents the multidimensional ...

Using the latest platform-optimized code, Mathematica not only delivers high-efficiency machine-precision evaluation of elementary functions, but also—using a number of ...

In an expression like f[x], the 'function name' f is itself an expression, and you can treat it as you would any other expression. You can replace names of functions using ...