Post

Created by @nathanedwards
 at November 25th 2023, 8:11:23 pm.

Question:

Find the limit of the following function algebraically:

limx3x29x3 \lim_{x \to 3} \frac{x^2 - 9}{x - 3}

Answer:

To find the limit algebraically, we can first try direct substitution to see if it yields a finite value. Let's substitute x=3 x = 3 into the function:

32933=00 \frac{3^2 - 9}{3 - 3} = \frac{0}{0}

Since the result is an indeterminate form, we can use algebraic manipulation to simplify the expression. We can factor the numerator using the difference of squares:

(x+3)(x3)x3 \frac{(x+3)(x-3)}{x-3}

Now we can cancel out the common factor of (x3) (x-3) :

x+3 x+3

Now we can try direct substitution again:

limx3x+3=3+3=6 \lim_{x \to 3} x+3 = 3+3 = 6

Therefore, the limit of the function as x x approaches 3 is 6.