(a)
\The function is .
Graph :
\Graph the function :
Observe the graph.
\As tends to
from left hand side, the value of
approaches to
.
So .
As tends to
from right hand side, the value of
approaches to
.
So .
Left hand limit and right hand limit are equal, so is exist.
Therefore .
(b)
\The function is .
Construct the table with nearest value of , to estimate the value of
:
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Observe the table.
\The value of at
is
and the value of
at
is
.
Therefore the value of at
is
.
.
.