Using calculus to see if the function f(x) is continuous at a point (point c) involves three steps. These three conditions must be met:
1. f(c) exists, is defined
2. lim f(x) exists
x-->c
3. f(c)= lim f(x)
x-->c
Wherever a function is differentiable, it must also be continuous. The opposite is not true, however. For example, the absolute value function, f(x) =|x|, is not differentiable at x=0 even though it is continuous everywhere.
That's true. If a function is continuous, it's (Riemman) integrable, but the converse is not true.
If the function is continuous in the interval [a,b] where f(a)*f(b) < 0 (f(x) changes sign ) , then there must be a point c in the interval a<c<b such that f(c) = 0 . In other words , continuous function f in the interval [a,b] receives all all values between f(a) and f(b)
"Removable discontinuity" means the function is not defined at that point (it has a "hole"), but by changing the function definition at that single point, defining it to be certain value, it becomes continuous. "Irremovable discontinuity" means the function makes a sudden jump at that point. There are infinitely many functions like that; for example, you can set the function to be: f(x) is undefined at x = -2 f(x) = 0 for x < 2 (except for x = -2) f(x) = 1 for x > 2
Υou show that it is continuous in every element of it's domain.
All differentiable functions need be continuous at least.
If the graph of the function is a continuous line then the function is differentiable. Also if the graph suddenly make a deviation at any point then the function is not differentiable at that point . The slope of a tangent at any point of the graph gives the derivative of the function at that point.
Yes. The cosine function is continuous. The sine function is also continuous. The tangent function, however, is not continuous.
Yes.If you find 2 relative minima and the function is continuous, there must be exactly one point between these minima with the highest value in that interval. This point is a relative maxima.Think of temperature for example (it is continuous).
Wherever a function is differentiable, it must also be continuous. The opposite is not true, however. For example, the absolute value function, f(x) =|x|, is not differentiable at x=0 even though it is continuous everywhere.
yes it is a continuous function.
Four discrete points do not define a continuous function.
A piece-wise continuous function is one which has a domain that is broken up inot sub-domains. Over each sub-domain the function is continuous but at the end of the domain one of the following possibilities can occur:the domain itself is discontinuous (disjoint domains),the value of the function is not defined at the start or end-point of the domain ((a hole),the value of the function at the end point of a sub-domain is different to its value at the start of the next sub-domain (a step-discontinuity).A piece-wise continuous function is one which has a domain that is broken up inot sub-domains. Over each sub-domain the function is continuous but at the end of the domain one of the following possibilities can occur:the domain itself is discontinuous (disjoint domains),the value of the function is not defined at the start or end-point of the domain ((a hole),the value of the function at the end point of a sub-domain is different to its value at the start of the next sub-domain (a step-discontinuity).A piece-wise continuous function is one which has a domain that is broken up inot sub-domains. Over each sub-domain the function is continuous but at the end of the domain one of the following possibilities can occur:the domain itself is discontinuous (disjoint domains),the value of the function is not defined at the start or end-point of the domain ((a hole),the value of the function at the end point of a sub-domain is different to its value at the start of the next sub-domain (a step-discontinuity).A piece-wise continuous function is one which has a domain that is broken up inot sub-domains. Over each sub-domain the function is continuous but at the end of the domain one of the following possibilities can occur:the domain itself is discontinuous (disjoint domains),the value of the function is not defined at the start or end-point of the domain ((a hole),the value of the function at the end point of a sub-domain is different to its value at the start of the next sub-domain (a step-discontinuity).
Yes, a polynomial function is always continuous
That's true. If a function is continuous, it's (Riemman) integrable, but the converse is not true.
Weistrass function is continuous everywhere but not differentiable everywhere
Intuitively, a continuous function y = f(x) is one where small changes in x result in small changes in y. More rigorously, consider the function y = f(x) defined on the domain D to the codomain C where both D and C are subsets of R. Then f(x) is continuous at a point p in D if the limit of f(x) as x approaches p within D is f(p). The function is said to be continuous is it is continuous at every point in its domain. The domain and codomain of f can be extended to multiple dimensions provided a suitable metric (eg Pythagorean distance) is used.