{"id":4055,"date":"2021-08-15T15:03:10","date_gmt":"2021-08-15T15:03:10","guid":{"rendered":"https:\/\/mathemerize.com\/?p=4055"},"modified":"2022-01-27T16:36:46","modified_gmt":"2022-01-27T11:06:46","slug":"algebraic-operations-on-functions","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/algebraic-operations-on-functions\/","title":{"rendered":"Algebraic Operations on Functions"},"content":{"rendered":"
Here you will learn algebraic operations on functions, equal or identical functions and homogeneous function.<\/p>\n
Let’s begin –<\/p>\n
Various operations, namely addition, subtraction, multiplication, division etc on real function are :<\/p>\n
(i) Addition<\/strong> : Let f : \\(D_1\\) \\(\\rightarrow\\) R and g : \\(D_2\\) \\(\\rightarrow\\) R be two real functions. Then, their sum f + g is defined from \\(D_1 \\cap D_2\\) to R which associates each x \\(\\in\\) \\(D_1 \\cap D_2\\) to the number f(x) + g(x). It is defined as<\/p>\n (f + g) (x) = f(x) + g(x)\u00a0 for all\u00a0 x \\(\\in\\) \\(D_1 \\cap D_2\\)<\/p>\n (ii) Difference (Subtraction)<\/strong> : Let f : \\(D_1\\) \\(\\rightarrow\\) R and g : \\(D_2\\) \\(\\rightarrow\\) R be two real functions. Then, the difference of g from f is denoted by f – g and is defined as<\/p>\n (f – g) (x) = f(x) – g(x)\u00a0 for all\u00a0 x \\(\\in\\) \\(D_1 \\cap D_2\\)<\/p>\n (iii) Product<\/strong> : Let f : \\(D_1\\) \\(\\rightarrow\\) R and g : \\(D_2\\) \\(\\rightarrow\\) R be two real functions. Then, their product (or pointwise multiplication) f g is a function \\(D_1 \\cap D_2\\) to R and is defined as<\/p>\n (f g) (x) = f(x) g(x)\u00a0 for all\u00a0 x \\(\\in\\) \\(D_1 \\cap D_2\\)<\/p>\n (iv) Quotient<\/strong> : Let f : \\(D_1\\) \\(\\rightarrow\\) R and g : \\(D_2\\) \\(\\rightarrow\\) R be two real functions. Then, the quotient of f by g is denoted by \\(f\\over g\\) and it is a function from \\(D_1 \\cap D_2\\) – {x : g(x) = 0} to R defined by<\/p>\n (\\(f\\over x\\))(x) = \\(f(x)\\over g(x)\\) for all\u00a0 x \\(\\in\\) \\(D_1 \\cap D_2\\) – {x : g(x) = 0}<\/p>\n (v) Multiplication of a function by a scalar<\/strong> : Let f : D \\(\\rightarrow\\) R be a real function and \\(\\alpha\\) be a scalar (real number). Then the product \\(\\alpha\\)f is a function from D to R and is defined as<\/p>\n \\(\\alpha f\\) (x) = \\(\\alpha\\) f(x) for all x \\(\\in\\) D<\/p>\n\n\n Example : <\/span> Find the domain of the function y = \\(log_{(x-4)}(x^2 – 11x + 24)\\).<\/p>\n Solution : <\/span>Here ‘y’ would assume real value if, A function is said to be bounded if there exists a finite M such that |f(x)| \\(\\le\\) M, \\(\\forall\\) x \\(\\in\\) \\(D_f\\).<\/p>\n\n\n
\n x – 4 > 0 and \\(\\ne\\) 1, \\(x^2 -11x + 24\\) > 0 \\(\\implies\\) x > 4 and \\(\\ne\\) 5, (x-3)(x-8) > 0
\n \\(\\implies\\) x > 4 and \\(\\ne\\) 5, x < 3 or x > 8 \\(\\implies\\) x > 8 \\(\\implies\\) Domain (y) = (8, \\(\\infty\\))
<\/p>\n\n\nBounded Function<\/strong><\/h4>\n