Saturday, October 18, 2014

Where is the function f(x) discontinuous? f(x) = (x^2-x-2)/(x-2), if x is not 2 f(x) = 1, if x=2

For a function to be continuous, the values of the lateral
limits have to be equal and they are equal to the value of function, if we'll let x to
be equal to the value of accumulation point.


We'll
calculate the lateral limits, if x approaches to 2 from the left and from the
right:


lim (x^2-x-2)/(x-2) = lim (x-2)(x+1)/(x-2) = lim
(x+1) = 2+1 = 3


Now, we'll evaluate the limit if x =
2.


According to enunciation, f(2) =
1.


We notice that the limit of the function, if x
approaches to 2, is not equal to the value of the function
f(2).


The function is discontinuous at x =
2.

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