Note: Use only in the MuPAD Notebook Interface. This functionality does not run in MATLAB. |
If a limit of a function at a particular value of a variable
does not exist, the limit
command
returns undefined
. For example, tan(x)
does
not have a bidirectional limit at
:
limit(tan(x), x = PI/2)
The plot of this function shows that the function can have two
different limits as the variable x
approaches the
value
from
the left and from the right:
plot(tan(x), x = -PI..PI)
To compute one-sided limits of a function, use the options Left
and Right
:
limit(tan(x), x = PI/2, Left); limit(tan(x), x = PI/2, Right)
If the function has a bidirectional limit at some point, one-sided limits are equal at this point. They also are equal to the bidirectional limit at this point:
Left = limit(abs(tan(x)), x = PI/2, Left); Right = limit(abs(tan(x)), x = PI/2, Right); Bidirectional = limit(abs(tan(x)), x = PI/2)
plot(abs(tan(x)), x = 0..PI)