expressions represent values and consist of variables, constants, and operators. they do not include an equals sign or assert equality.
algebraic expressions:
equations state that two expressions are equal and include an equals sign. they can be solved to find the values of the variables.
functions describe a relationship between inputs and outputs. each input corresponds to exactly one output.
piecewise functions
inequalities express a relationship where two expressions are not necessarily equal, but one is greater or less than the other.
the number of arguments or inputs a function takes.
types:
unary: a function with one input (eg '')
binary: a function with two inputs (eg '')
n-ary: a function with nn inputs (eg '')
the set of all possible inputs for the function.
example: for 'f(x) = sqrt(x)' the domain is 'x > 0'.
the set of all possible outputs of the function.
example: for 'f(x) = x ** 2', the range is 'y > 0'.
the set of values that could potentially be outputs, not necessarily all of which are achieved.
example: for 'f(real_numbers) -> real_numbers' the codomain is 'real_numbers' even if the range is only non-negative reals.
a function ff is injective if different inputs map to different outputs.
example: ''
a function ff is surjective if every element in the codomain is mapped by some element in the domain.
example: ''
a function is bijective if it is both injective and surjective.
example: ''
a function ff is continuous if small changes in the input result in small changes in the output.
example: 'f(x) = x ** 2' is continuous everywhere.
a function ff is differentiable if it has a derivative at each point in its domain.
example: 'f(x) = x ** 3' is differentiable everywhere.
a function ff is periodic if there exists a positive number tt such that f(x+t)=f(x)f(x+t)=f(x) for all xx.
example: 'f(x) = sin(x)' has a period of '2 pi'.
even function: 'f(-x) = f(x)' for all 'x' in the domain
odd function: 'f(-x) = -f(x)' for all 'x' in the domain
example: 'f(x) = x ** 3'
a function is monotonic if it is either entirely non-increasing or non-decreasing.
types:
a function ff is bounded if there exists a number mm such that ∣f(x)∣≤m∣f(x)∣≤m for all xx in the domain.
types:
a function 'f' has an inverse 'f ** -1' if 'f((f ** -1)(y)) = y' and '(f ** -1)(f(x)) = x'
example: the inverse of 'f(x) = 2 x' is '(f ** -1)(x) = x / 2'
readable plaintext mathematics notation similar to what is used in programming languages
avoids symbol proliferation
operators, values, and other expressions must be separated by spaces
multiplication: *
exponentiation: **
division: /
subtraction: -
addition: +
application: function_name(argument, ...)
definition: function_name(parameter, ...) = ...
standard library
srqt()
expt()