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Limits. Why limits? What are limits? Types of Limits Where Limits Fail to Exist Limits Numerically and Graphically Properties of Limits Limits Algebraically Trigonometric Limits Average and Instantaneous Rates of Change Sandwich Theorem Formal Definition of a Limit. Why limits?.
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Limits Why limits? What are limits? Types of Limits Where Limits Fail to Exist Limits Numerically and Graphically Properties of Limits Limits Algebraically Trigonometric Limits Average and Instantaneous Rates of Change Sandwich Theorem Formal Definition of a Limit
Why limits? Limits help us answer the big question of how fast an object is moving at an instant of time. For Newton and Leibniz, this had to do with the velocity a planet moved in its orbit around the sun.
Why limits? We might be more interested in the velocity of other things
Why limits? Derivative The fundamental concepts of calculus - the derivative and the integral are both defined in terms of limits. We will see more of these as we learn how to use limits. Integral
Why limits? So limits are like the engine under the hood of a car. We are mainly interested in driving the car and won’t spend a lot of time thinking about what is happening under the hood, but we should have a basic understanding of how the engine works.
What are limits? Limits describe the behavior of functions around specific values of x. They also describe the end behavior of functions. More specifically, limits describe where the y-value of a function appears to be heading as x gets closer and closer to a particular value or as x approaches positive/negative infinity. Let’s look at these ideas a little closer.
What are limits? Some important notes about limits: a. Limits are real numbers, but we sometimes use to indicate the direction a function is heading.
What are limits? Some important notes about limits: b. Limitsdo not depend on the value of the function at a specific x value, but on where the function appears to be heading.
What are limits? For a limit to exist, the function must be heading for the same y-value whether the given x-value is approached from the left or from the right, i.e. one-sided limits must agree.
Types of Limits There are three basic forms of limits ( ): a. Limits at a finite value of x b. Infinite limits (vertical asymptotes) c. Limits at Infinity (horizontal asymptotes or end behavior)
Infinite Limits Infinite limits occur in the vicinity of vertical asymptotes. Functions may approach positive or negative infinity on either side of a vertical asymptote. Remember to check both sides carefully. Also, remember to simplify rational expressions before identifying vertical asymptotes.
Determine the limit of each function as x approaches 1 from the left and from the right. Infinite Limits Ex. 1
Identify all vertical asymptotes of the graph of each function. Infinite Limits Ex. 2
Remember: Limits at Infinity logarithmic polynomial exponential factorial ?????????? Evaluate:
Video Limits at Infinity
Jump Discontinuities Vertical Asymptotes Oscillating Discontinuities Where Limits Fail to Exist There are three places where limits do not exist:
Limits Numerically 1 Use the TblSet (with Independent set to ASK) and TABLE functions on your graphing calculator to estimate the limit.
Limits Numerically 2 Use the TblSet (with Independent set to ASK) and TABLE functions on your graphing calculator to estimate the limit.
Limits Numerically 3 Use the TblSet (with Independent set to ASK) and TABLE functions on your graphing calculator to estimate the limit.
Properties of Limits 1 Some examples: Thinking graphically may help here.
Use the information provided here to evaluate limits a – d here Properties of Limits 2 Ex. 1
Use the information provided here to evaluate limits a – d here Properties of Limits 2 Ex. 2
Properties of Limits 3 For example, evaluate the limit
Properties of Limits 4 For example:
Properties of Limits 5 For example, evaluate the limit
Properties of Limits 6 For example, given: Evaluate the limit:
In addition to Direct Substitution, there are many strategies for evaluating limits algebraically. In particular, we will focus on three of them: • Factor and Cancel • Simplifying Fractions • Rationalization Limits Algebraically
Basic Strategy: Multiply numerator and denominator by 3(3+x) and then simplify. You could also find a common denominator for both fractions in the numerator and then simplify that first. Simplifying Fractions
There are two special trigonometric limits: Trigonometric Limits
Trigonometric Limit Ex. 1 Basic strategy:
Strategy: Multiply numerator/denominator by 4 Trigonometric Limit Ex. 2 Let and note that as ,