SOLUTION: Explain a process for finding a limit . Write a concise description of the meaning of lim f(x)=10 as x approaches to 3 . Examine the continuity of g(x) = x+3 and the point x=2.

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Question 179643: Explain a process for finding a limit
.
Write a concise description of the meaning of lim f(x)=10 as x approaches to 3
.
Examine the continuity of g(x) = x+3 and the point x=2.

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Explain a process for finding a limit
.
Write a concise description of the meaning of lim f(x)=10 as x approaches to 3



means, colloqually, for any required degree of tolerance
epsilon, (a positive number usually thought of as very small)
there exists another positive number delta (also usually thought 
of as very small) such that whenever x is less than delta units 
away from 3, f%28x%29 will always be less than epsilon units away from 10.

To write it concisely,

For any matrix%281%2C3%2Cepsilon%2C+%22%3E%22%2C+0%29, there exists a 
matrix%281%2C3%2Cdelta%2C+%22%3E%22%2C+0%29  such that matrix%281%2C3%2Cabs%28f%28x%29-10%29%2C+%22%3C%22%2C+epsilon%29 whenever matrix%281%2C5%2C0%2C+%22%3C%22%2C+abs%28x-3%29%2C+%22%3C%22%2C+delta%29.

Examine the continuity of g(x) = x+3 and the point x=2.

g%28x%29 will be continuous at x=2 if g%282%29=2%2B3=5 and

       

Suppose we have any required tolerance, epsilon%3E0. Then
we need to find a delta%3E0 such that if 0%3Cabs%28x-2%29%3Cdelta,
then abs%28g%28x%29-5%29%3Cepsilon.

abs%28g%28x%29-5%29%3Cepsilon if and only if
abs%28%28x%2B3%29-5%29%3Cepsilon if and only if
abs%28x%2B3-5%29%3Cepsilon if and only if
abs%28x-2%29%3Cepsilon

So we simply take any d such that 
delta%3Cepsilon and then turn the above 
backwards and we have:

abs%28x-2%29%3Cdelta => abs%28x-2%29%3Cepsilon =>
abs%28x%2B3-5%29%3Cepsilon => abs%28g%28x%29-5%29%3Cepsilon

Edwin