Flashcards in 2.2.4 An Overview of Limits Deck (11):
An Overview of Limits
• The limit is the range value that a function approaches as you get closer to a particular domain value.
• An indeterminate form is a mathematically meaningless expression.
- This limit involves an unusual variable.
- Remember to use direct substitution as a first step in evaluating limits. In this case, direct substitution produces the familiar indeterminate formof 0/0.
- Proceed by factoring the numerator, which is a difference of two squares.
- Use cancellation to simplify the limit expression and then apply direct substitution to arrive at the result.
- The existence of limits can be demonstrated graphically. On the far left, the graph shows that near x= 7 the function is approaching the same value from both the left and the right. The limit exists and equals that value, even though the function takes on a different value at x= 7.
- On the near left, the graph approaches different values on either side of x= 5. Since the two one-sided limits have different values, the limit of the function does not exist.
- Here is an example of a function that is approaching very large values from the one side and very small values from the other. The limit for such a function does not exist.
LetG(x)= x^2−4/x+2, x≠−2
Find the value of k so that lim x→−2 G(x)=G(−2).
Classify all of the discontinuities of the function h(x)=f(g(x)) given f(x)=1/x−3 and g(x)=x^2+2.
x = −1 and x = 1; infinite discontinuities
Given that lim x→0(sinx)^2/x=0, find the limit.
lim x→0 1−cosx/x
Evaluate the limit limCOW→3
[4(COW)−12 / (COW)^2+(COW)−12].
Does f (x) have a limit at x = −3?
No, the limit doesn’t exist.
Evaluate the limit
evaluate the limit lim x→−1 f(x).
The limit does not exist.
Given the limit lim x→2(2x+2)=6, what is the largest value of δ such that ε