{"id":4052,"date":"2021-08-15T14:49:02","date_gmt":"2021-08-15T14:49:02","guid":{"rendered":"https:\/\/mathemerize.com\/?p=4052"},"modified":"2022-01-16T16:56:54","modified_gmt":"2022-01-16T11:26:54","slug":"types-of-functions-in-maths","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/types-of-functions-in-maths\/","title":{"rendered":"Types of Functions in Maths – Domain and Range"},"content":{"rendered":"
Here you will learn types of functions in maths i.e polynomial function, logarithmic function etc and their domain and range.<\/p>\n
Let’s begin –<\/p>\n
If a function is defined by f(x) = \\(a_0x^n\\) + \\(a_1x^{n-1}\\) + \\(a_2x^{n-2}\\) + ….. + \\(a_{n-1}x\\) + \\(a_n\\) where n is a non negative integer and \\(a_0\\), \\(a_1\\), \\(a_2\\), ….. , \\(a_n\\) are real numbers and \\(a_0\\) \\(\\ne\\) 0, then f is called a polynomial function of degree n. If n is odd, then polynomial is of odd degree, if n is even, then the polynomial is of even degree.<\/p>\n
Note :<\/strong><\/p>\n (i) Range of odd degree polynomial is always R.<\/p>\n (ii) Range of even degree polynomial is never R.<\/p>\n (iii) A Polynomial of degree one with no constant term is called an odd linear function. i.e. f(x) = ax, (iv) f(x) = ax + b, a \\(\\ne\\) 0 is a linear polynomial.<\/p>\n (v) f(x) = c, is a non linear polynomial(its degree is zero).<\/p>\n (vi) f(x) = 0, is a polynomial but its degree is not defined.<\/p>\n (vii) There are two polynomial functions, satisfying the relation;<\/p>\n f(x).f(1\/x) = f(x) + f(1\/x). They are :<\/p>\n (a) f(x) = \\(x^n\\) + 1 and (b) f(x) = 1 – \\(x^n\\), where n is a positive integer.<\/p>\n A function f is called an algebraic function if it can be constructed using algebraic operations(such as addition, subtraction, multiplication, division, and taking radicals) within polynomials.<\/p>\n Note :<\/strong><\/p>\n (i) All polynomial functions are algebraic but not the converse.<\/p>\n (ii) A function that is not algebraic is called Transcendental function.<\/p>\n A rational function is a function of the form y = f(x) = \\(g(x)\\over h(x)\\), where g(x) & h(x) are polynomials & h(x) \\(\\ne\\) 0,<\/p>\n Domain :<\/strong> R – {x | h(x) = 0}<\/p>\n Any algebraic function is automatically an algebraic function.<\/p>\n f(x) = sinx f(x) = cosx f(x) = tanx f(x) = cosecx f(x) = secx f(x) = cotx A function f(x) = \\(a^x\\)(a > 0), a \\(\\ne\\) 1, x \\(\\in\\) R is called an exponential function. The inverse of the exponential function is called the logarithmic function, i.e. g(x) = \\(log_ax\\).<\/p>\n Note that f(x) & g(x) are inverse of each other.<\/p>\n Domain of \\(a^x\\) is R Range \\(R^+\\)<\/p>\n Domain of \\(log_ax\\) is \\(R^+\\) Range R<\/p>\n A function y = f(x) = |x| is called the absolute value function or modulus function. It is defined as :<\/p>\n y = |x| = [x if x \\(\\le\\) 0 -x if x < 0]<\/p>\n For f(x) = |x|, domain is R and range is [0,\\(\\infty\\)]<\/p>\n For f(x) = \\(1\\over{|x|}\\), domain is R – {0} and range is \\(R^+\\)<\/p>\n A function y = f(x) = Sgn(x) is defined as follows :<\/p>\n y = f(x) = [ 1 for x > 0 0 for x = 0 -1 for x < 0 ]<\/p>\n Domain : R<\/p>\n Range : [-1, 0, 1]<\/p>\n The function y = f(x) = [x] is called the greatest integer function where [x] denotes the greatest integer less than or equal to x. Note that for :<\/p>\n\n\n <\/p>\n\n\n It is defined as : g(x) = {x} = x – [x] e.g. the fractional part of the number 2.1 is 2.1 – 2 = 0.1 and the fractional part of -3.7 is 0.3. The period of this function is 1.<\/p>\n The function f : A \\(\\rightarrow\\) A defined by f(x) = x \\(\\forall\\) x \\(\\in\\) A is called the identity of A and is denoted by \\(I_A\\). It is easy to observe that identity function defined on R is bijection.<\/p>\n The function f : A \\(\\rightarrow\\) B is said to be a constant function if every element of A has the same f image in B. Thus f : A \\(\\rightarrow\\) B ; f(x) = c, \\(\\forall\\) x \\(\\in\\) A, c \\(\\in\\) B is a constant function. Note that the range of constant function is singleton.<\/p>\n Hope you learnt types of functions in maths and to learn more practice more questions and get ahead in competition. Good Luck!<\/p>\n\n\n
a \\(\\ne\\) 0<\/p>\n(b) Algebraic Function<\/strong><\/h4>\n
(c) Rational Function<\/strong><\/h4>\n
(d) Trigonometric Functions<\/strong><\/h4>\n\n\n
(i) Sine Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R
\n\t\t Range :<\/b> [-1, 1], period 2\\(\\pi\\)<\/p>
\n\n\t\t (ii) Cosine Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R
\n\t\t Range :<\/b> [-1, 1], period 2\\(\\pi\\)<\/p>
\n\n\t\t (iii) Tangent Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R – {x | x = \\({(2n+1)\\pi\\over 2}\\), n \\(\\in\\) I }
\n\t\t Range :<\/b> R, period \\(\\pi\\)<\/p>
\n\n\t\t (iv) Cosecant Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R – { x | x = n\\(\\pi\\), n \\(\\in\\) I }
\n\t\t Range :<\/b> R – (-1, 1), period 2\\(\\pi\\)<\/p>
\n\n\t\t (v) Secant Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R – { x | x = (2n+1)\\(\\pi\\)\/2, n \\(\\in\\) I }
\n\t\t Range :<\/b> R – (-1, 1), period 2\\(\\pi\\)<\/p>
\n\n\t\t (vi) Cotangent Function<\/h4>\n\n\t\t
\n\t\t Domain :<\/b> R – { x | x = n\\(\\pi\\), n \\(\\in\\) I }
\n\t\t Range :<\/b> R, period \\(\\pi\\)
<\/p>\n\n\n(e) Exponential and Logarithmic function<\/strong><\/h4>\n
(f) Absolute Value Function<\/strong><\/h4>\n
(g) Signum Function<\/strong><\/h4>\n
(h) Greatest integer or step up function<\/strong><\/h4>\n
\n
\n x<\/td>\n [x]<\/td>\n <\/tr>\n \n [-2,-1]<\/td>\n -2<\/td>\n <\/tr>\n \n [-1,0]<\/td>\n -1<\/td>\n <\/tr>\n \n [0,1]<\/td>\n 0<\/td>\n <\/tr>\n \n [1,2]<\/td>\n 1<\/td>\n <\/tr>\n <\/tbody><\/table>
\n Domain :<\/b> R
\n Range :<\/b> I\n (i) Fractional part function<\/strong><\/h4>\n
(j) Identity function<\/strong><\/h4>\n
(j) Constant function<\/strong><\/h4>\n