How do you use a graphing calculator to find the limit of #x^2-5x# as x approaches -1?

1 Answer
Steve M
Apr 8, 2017

# lim_(x rarr -1) x^2-5x =6#

Explanation:

Use the calculator to plot the function and look at what happens near and at #x=-1#.

In this case as the function is a polynomial, it is "well behaved", and the limit is found by substituting #x=-1# to give:

# lim_(x rarr -1) x^2-5x = 1+5 = 6#

As can be confirmed by the graph:
graph{x^2-5x [-2, 6, -4, 8]}

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