(i) Constant Function:
A function is said to be a constant function if there is a real number such that .
Hence which is singleton.
, the line parallel to .
(ii) Identify function:
For any non-empty set , the function is defined by is called the identity function on . It is denoted by .
The line plotted through origin.
(iii) Polynomial Function:
A function defined by , where is a non-negative integer and are real constant with , is called a polynomial function or a polynomial of degree .
(iv) Rational Function:
A function , where & are polynomials with , is called a rational function.
(v) Modulus function:
If is defined by
is called Modulus function.
The modulus function is also known as absolute value function.
Its domain and rage is
(vi) Signum function:
The signum function on is defined by
The range of is .
(vii) Exponential function:
An exponential function is defined by
The fact that exists for every .
(d) If then
(e) is closer to the -axis as recedes away from zero along negative values.
(viii) Logarithmic function:
The function defined by where is called the logarithmic function.
The graphs meets the -axis at and never meet the – axis.
Some Logarithmic function:
(g) If and if
(ix) Greatest Integer Function:
The function is defined by
where is the greatest integer not greater that (less than or equal to ) is called the greatest integer function.
The graph consists of infinitively many closed open parallel line segments.