{"id":3844,"date":"2021-08-09T10:06:54","date_gmt":"2021-08-09T10:06:54","guid":{"rendered":"https:\/\/mathemerize.com\/?p=3844"},"modified":"2021-11-21T01:06:15","modified_gmt":"2021-11-20T19:36:15","slug":"intermediate-value-theorem","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/intermediate-value-theorem\/","title":{"rendered":"Intermediate Value Theorem Example and Statement"},"content":{"rendered":"
Here, you will learn intermediate value theorem example and statement and single point continuity.<\/p>\n
Statement :<\/strong> Suppose f(x) is continuous on an interval I, and a and b are any two points of I. Then if \\(y_0\\) is a number between f(a) and f(b), there exist a number c between a and b such that f(c) = \\(y_0\\).<\/p>\n Note that a function f which is continuous in [a,b] possesses the following properties :<\/p>\n (i) If f(a) & f(b) posses opposite signs, then there exists at least one root of the equation f(x) = 0 in the open interval (a,b).<\/p>\n (ii) If K is any real number between f(a) & f(b), then there exist atleast one root of the equation f(x) = K in the open interval (a,b).<\/p>\n<\/blockquote>\n\n\n Example : <\/span>Show that the function, f(x) = \\((x – a)^2\\) \\((x – b)^2\\) + x, takes the value \n\t \\(a + b\\over 2\\) for some \\(x_0\\) \\(\\in\\) (a, b)<\/p>\n\t Solution : <\/span>f(x) = \\((x – a)^2\\) \\((x – b)^2\\) + x (a) If f(x) is continuous & g(x) is discontinuous at x = a then the product function \\(\\phi (x)\\) = f(x).g(x) will not necessarily be discontinuous at x = a,<\/p>\n For e.g. f(x) = x & g(x) = \\(sin{\\pi\\over x}\\) at x \\(\\ne\\) 0 and g(x) = 0 at x = 0<\/p>\n f(x) is continuous at x = 0 & g(x) is discontinuous at x = 0, but f(x).g(x) is continuous at x = 0.<\/p>\n (b) If f(x) and g(x) both are discontinuous at x = a then the product function \\(\\phi (x)\\) = f(x).g(x) is not necessarily be discontinuous at x = a,<\/p>\n For e.g. f(x) = -g(x) = [1 at x \\(\\geq\\) 0 -1 at x < 0]<\/p>\n f(x) & g(x) both are discontinuous at x = 0, but the product function f(x).g(x) is still continuous at x = 0, but the product function f(x).g(x) is still continuous at x = 0.<\/p>\n (c) If f(x) and g(x) both are discontinuous at x = a then f(x) \\(\\pm\\) g(x) is not necessarily be discontinuous at x = a.<\/p>\n (d) A continuous function whose domain is closed must have a range also in closed interval.<\/p>\n (e) If f is continuous at x = a & g is continuous at x = f(a) then the composite g[f(x)] is continuous at x = a.<\/p>\n Functions which are continuous only at one point are said to exhibit single point continuity.<\/p>\n\n\n\n
f(a) = a & f(b) = b
& \\((a + b)\\over 2\\) \\(\\in\\) (f(a), f(b))
\\(\\therefore\\) By intermediate value theorem, there is at least one \\(x_0\\) \\(\\in\\) (a, b) such that f(\\(x_0\\)) = \\((a + b)\\over 2\\)
<\/p>\n\n\nSome Important Points on Continuity<\/h2>\n
Single Point Continuity<\/h2>\n