How do you find #\lim _ { x \rightarrow 7} \frac { x ^ { 3} - 343} { x - 7}#?
1 Answer
Jan 27, 2018
Explanation:
Direct substitution does not work because it gives us 0/0, an indeterminate form.
We could try factorising this rational function so that we can possibly cancel out common terms.
The factorised numerator is:
The denominator cannot be factorised further.
Therefore, we find that
We can cancel the
We get
If we substitute
This is the graph below.
graph{(x^3-343)/(x-7) [-24.6, 25.38, 129.5, 154.49]}