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3.2: Continuity. Objectives: To determine whether a function is continuous Determine points of discontinuity Determine types of discontinuity Apply the Intermediate Value Theorem. CONTINUITY AT A POINT—No holes, jumps or gaps!!. A function is continuous at a point c if:
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3.2: Continuity Objectives: To determine whether a function is continuous Determine points of discontinuity Determine types of discontinuity Apply the Intermediate Value Theorem
CONTINUITY AT A POINT—No holes, jumps or gaps!! A function is continuous at a point c if: 1.) f(c) is defined 2.) exists 3.) = f(c) A FUNCTION NEED NOT BE CONTINUOUS OVER ALL REALS TO BE A CONTINUOUS FUNCTION
Does f(2) exist? Does exist? Does exist? Is f(x)continuous at x = 2? Do the same for x= 1, 3, and 4.
Removable discontinuity • Limit exists at c but f(c)≠ the limit • Can be fixed. Set f(c) = • This is called a continuous extension
Example: Find the values of x where the function is discontinuous.
OTHER TYPES OF DISCONTINUITY • JUMP: ( RHL ≠ LHL) • INFINITE: • OSCILLATING
Continuity on a closed interval A function is continuous on a closed interval [a,b] if: • It is continuous on the open interval (a,b) • It is continuous from the right at x=a: • It is continuous from the left at x=b:
example IT IS CONTINUOUS ON ITS DOMAIN.
A continuous function is one that is continuous at every point in its domain. It need not be continuous on all reals. Where are the functions discontinuous? If it is removable discontinuity, fix it!!
Find the value of the constant k that makes the function continuous.
Intermediate Value Theorem (IVT) A function y=f(x) that is continuous on a closed interval [a,b] takes on every value between f(a) and f(b). THE FUNCTION MUST BE CONTINUOUS ON INTERVAL!!
If f is continuous on [a,b] and f(A)and f(b) differ in signs, then there must be zero on [a,b]. 1. Show that f(x)=x3+2x-1 has a zero in [0, 1]. 2. Is any real number exactly 1 less than its cube?