{"id":3665,"date":"2021-08-05T23:46:17","date_gmt":"2021-08-05T23:46:17","guid":{"rendered":"https:\/\/mathemerize.com\/?p=3665"},"modified":"2021-11-24T16:13:53","modified_gmt":"2021-11-24T10:43:53","slug":"domain-and-range-of-greatest-integer-function","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/domain-and-range-of-greatest-integer-function\/","title":{"rendered":"Domain and Range of Greatest Integer Function"},"content":{"rendered":"
Here, you will learn domain and range of greatest integer function and properties of greatest integer function with example.<\/p>\n
Let’s begin –<\/p>\n
For any real number x, we use the symbol [x] or \\(\\lfloor x \\rfloor\\) to denote the greatest integer less than or equal to x. For example,<\/p>\n
[2.75] = 2, [3] =3, [0.74] = 0, [-7.45] = -8 etc.<\/p>\n
\nThe Function f : R \\(\\rightarrow\\) R defined by f(x) = [x] for all x \\(\\in\\) R<\/strong> is called the greatest integer function or the floor function.<\/p>\n<\/blockquote>\n
It is also called a step function.<\/p>\n
Domain and Range<\/h2>\n
Clearly. domain<\/strong> of the greatest integer function is the set of all real numbers and the range<\/strong> is the set Z of all integers as it attains only integer values.<\/p>\n
\nDomain : R<\/strong><\/p>\n
Range : Z<\/strong><\/p>\n<\/blockquote>\n
The graph of the greatest integer function is shown in figure.<\/p>\n
<\/p>\n
Greatest integer function<\/strong><\/p>\n
Properties of Greatest Integer Function<\/h2>\n
If n is an integer and x is a real number between n and n + 1, then<\/p>\n
(i) [-n] = -[n]<\/p>\n
(ii) [x + k] = [x] + k, for any integer k.<\/p>\n
(iii) [-x] = -[x] – 1<\/p>\n
(iv) [x] + [-x] = \\(\\begin{cases} -1, & \\text{if}\\ x \\notin Z \\\\
0, & \\text{if}\\ x \\in Z \\end{cases}\\)<\/p>\n(v) [x] – [-x] = \\(\\begin{cases} 2[x] + 1, & \\text{if}\\ x \\notin Z \\\\
2[x], & \\text{if}\\ x \\in Z \\end{cases}\\)<\/p>\n(vi) [x] \\(\\ge\\) k \\(\\implies\\) x > k, where k \\(\\in\\) Z<\/p>\n
(vii) [x] > k \\(\\implies\\) x \\(\\ge\\) k + 1, where k \\(\\in\\) Z<\/p>\n
(viii) [x] > k \\(\\implies\\) x \\(\\ge\\) k + 1, where k \\(\\in\\) Z<\/p>\n
(ix) [x] < k \\(\\implies\\) x < k, where k \\(\\in\\) Z<\/p>\n
(x) [x + y] = [x] + [y + x – [x]] for all x, y \\(\\in\\) R<\/p>\n\n\n
Example : <\/span> If y = 2[x] + 3 & y = 3[x – 2] + 5, then find [x + y] where [.] denotes greatest integer function.<\/p>\n
Solution : <\/span>y = 3[x – 2] + 5 = 3[x] – 1
\n so 3[x] – 1 = 2[x] + 3
\n [x] = 4 \\(\\implies\\) 4 \\(\\le\\) x < 5
\nthen y = 11
\nso x + y will lie in the interval [15, 16)
\nso [x + y] = 15
\n <\/p>\n\n\nHope you learnt domain and range of greatest integer function, learn more concepts of function and practice more questions to get ahead in the competition. Good luck!<\/p>\n\n\n