Formal Epsilon-Delta Definition of a Limit

Formal Epsilon-Delta Definiton of a Limit of a Function as x Approaches a Constant
Definition: [br]Given a function f and real numbers c and L, we say that [math]\frac{lim}{x\longrightarrow c}f\left(x\right)=L[/math] if and only if[br]for any [math]\varepsilon[/math] > 0 there exists a [math]\delta[/math] > 0 such that [br]if c - [math]\delta[/math] < x < c + [math]\delta[/math], x [math]\ne[/math] c then L - [math]\varepsilon[/math] < [math]f\left(x\right)[/math] < L + [math]\varepsilon[/math].[br][br]This applet is designed to give a graphical interpretation of this formal definition.[br][br]Enter a desired function into the input box for f(x).[br]Choose a value for c by typing into its input box.[br]Determine the appropriate value for the limit L and type it into its input box.[br]Choose a value for epsilon ([math]\varepsilon[/math]) by adjusting its slider or typing into its input box.[br]Choose an appropriate corresponding value for delta ([math]\delta[/math]) by adjusting its slider or typing into its input box.[br][br]If you can find an appropriate value of delta no matter how small the value of epsilon then you have demonstrated that the limit value L is correct.
Question 1
What are the coordinates of the center of the purple box?
Question 2
What are the height and width of the purple box?
Question 3
What is the significance of the purple box? For a particular value of epsilon, how do we adjust delta so that the inequalities in the definition of the limit are satisfied?
Question 4
For a particular value of epsilon, how can we see the largest corresponding value of delta so that the inequalities in the definition are satisfied?
Question 5
What do we need to do if a smaller value of epsilon is chosen?
Question 6
How can we tell from this exploration that the function has the limit that we specified?
Question 7
How do we modify the definition and illustration for a right limit?
Question 7
How do we modify the definition and illustration for a Left Limit?
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Information: Formal Epsilon-Delta Definition of a Limit