Finding limits of piece-wise functions.

Cardboard

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Hello forum! I'm sorry to bother you once again, but I need help with finding the limit of several piece-wise functions.

15mzdcp.jpg


Is this the correct way to approach this problem?

(a) Since -6 is being approached from the left side, that would mean the value as x approaches -6 are smaller than -6, thus making me apply the first function which is g(x) = 0?

(b) Since -6 is being approached from the right side, that means the value of x as it approaches -6 is larger than -6, so that would mean g(x) = x? And would I just leave it as x for the answer, or should I plug in the the limit -6 for x?

(c) Since -6 is being approached ambiguously from both sides, that would make me apply the middle formula, which is g(x) = sqrt(36-x^2)? And would I plug in -6 for x, which would result with sqrt(36-(-6)^2) -> sqrt (36 + 36) = sqrt(72) = 8.485?

(d) Now we have 6 instead of -6. If 6 is being approached from the left, that means the value of x as it approaches 6 is less than 6, which would make me apply the first function, which is g(x) = 0.

(e) 6 is being approached from the right, which means the value of x as it approaches 6 is larger than 6. That would mean that I should apply the third function, which is g(x) = x, and we put 6 for x since that is what x is approaching.

(f) Now we have 6 being approached from both the left and right which would imply that the middle function would be applied, which is g(x) = sqrt(36-x^2). Then sqrt(36-(6)^2) would result in sqrt(36-36) or square root of 0. Would that mean no limit exists?

Here is another one.

29ig04.jpg


For this would I simply conclude that there is no way for me to state the value of the limit?
 
Cardboard said:
Hello forum! I'm sorry to bother you once again, but I need help with finding the limit of several piece-wise functions.

15mzdcp.jpg


Is this the correct way to approach this problem?

(a) Since -6 is being approached from the left side, that would mean the value as x approaches -6 are smaller than -6, thus making me apply the first function which is g(x) = 0?

(b) Since -6 is being approached from the right side, that means the value of x as it approaches -6 is larger than -6, so that would mean g(x) = x? And would I just leave it as x for the answer, or should I plug in the the limit -6 for x?

(c) Since -6 is being approached ambiguously from both sides, that would make me apply the middle formula, which is g(x) = sqrt(36-x^2)? And would I plug in -6 for x, which would result with sqrt(36-(-6)^2) -> sqrt (36 + 36) = sqrt(72) = 8.485?

(d) Now we have 6 instead of -6. If 6 is being approached from the left, that means the value of x as it approaches 6 is less than 6, which would make me apply the first function, which is g(x) = 0.

(e) 6 is being approached from the right, which means the value of x as it approaches 6 is larger than 6. That would mean that I should apply the third function, which is g(x) = x, and we put 6 for x since that is what x is approaching.

(f) Now we have 6 being approached from both the left and right which would imply that the middle function would be applied, which is g(x) = sqrt(36-x^2). Then sqrt(36-(6)^2) would result in sqrt(36-36) or square root of 0. Would that mean no limit exists?

Here is another one.

29ig04.jpg


For this would I simply conclude that there is no way for me to state the value of the limit?

For problem (1)

First realize that f(x) is continuous at x=-6. We get f(-6)=0 by approaching from either side.

f(x) is NOT continuous at x = 6, because f(6[sup:33gwmi8i]-[/sup:33gwmi8i]) = 0 but f(6[sup:33gwmi8i]+[/sup:33gwmi8i]) = 6

Now think through your problem (around 6 and 6[sup:33gwmi8i]+[/sup:33gwmi8i]) again.

For #2, - what condition must the function satisfy - to be continuous at a point?
 
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