calculate the limit of x->2 (x^2-4)/(x-2)
1) Compute the limit of x2 -4x -2 as x → 2
ⓘ The power with a constant exponent is continuous here: substitute the limit of the base
The limit of x2 is 22 when x → 2
⇥1.1) Let's evaluate: 22
⇥ⓘ A power with a positive integer exponent is a repeated product: 22 = 2·2 = 4
⇥ 4
ⓘ The limit of a sum of finite limits is the sum of the limits
The limit of x2 -4 is 4 -4 when x → 2
⇥1.2) Let's evaluate: 4 -4
⇥ⓘ Start from 4 and move back 4 on the number line, down to zero: 4 -4 = 0
⇥ 0
ⓘ The limit of a sum of finite limits is the sum of the limits
The limit of x -2 is 2 -2 when x → 2
⇥1.3) Let's calculate: 2 -2
⇥ⓘ Start from 2 and move back 2 on the number line, down to zero: 2 -2 = 0
⇥ 0
For x2 -4x -2, we encounter the indeterminate form 0/0 as x tends to 2
2) To determine the limit, factor the numerator and denominator:
x2 -4
For x2 -4, we recognize a difference of two squares: x2 -22. Apply a2 -b2 = (a -b)·(a + b), with a = x and b = 2
Factors identified: (x + 2)·(x -2)
3) Let's simplify: (x + 2)·(x -2)x -2
ⓘ The original denominator must remain nonzero. The fraction is simplified by dividing the numerator and the denominator by their common factor x -2: (x + 2)·(x -2)x -2 = x + 2
x + 2
ⓘ The limit of a sum of finite limits is the sum of the limits
The limit of x + 2 is 2 + 2 when x → 2
Let's evaluate: 2 + 2
ⓘ Start from 2 and move forward 2 on the number line: 2 + 2 = 4
4
So the limit of x2 -4x -2 is 4 when x → 2
▶Limit:   4