Problem to solve
Compute \[ \lim_{ x \to 1 } \frac{x^3-1}{x-1} \]
Solution
STEP 1
Find the following limit:
lim_(x->1) (x^3 - 1)/(x - 1)
STEP 2
Hint: | Factor the numerator and denominator.
(x^3 - 1)/(x - 1) = ((x - 1) (x^2 + x + 1))/(x - 1):
lim_(x->1) ((x - 1) (x^2 + x + 1))/(x - 1)
STEP 3
Hint: | Cancel terms.
((x - 1) (x^2 + x + 1))/(x - 1) = x^2 + x + 1:
lim_(x->1)(x^2 + x + 1)
STEP 4
Hint: | The limit of a continuous function at a point is just its value there.
lim_(x->1)(x^2 + x + 1) = 1 + 1 + 1^2 = 3:
Answer: | 
 | 3