Math

QuestionFind limx1f(x)\lim _{x \rightarrow 1} f(x) for f(x)=x21x1f(x)=\frac{x^{2}-1}{\sqrt{x}-1}. Choices: (A) 4, (B) 2, (C) 0, (D) nonexistent.

Studdy Solution

STEP 1

Assumptions1. The function is defined as f(x)=x1x1f(x)=\frac{x^{}-1}{\sqrt{x}-1} . We need to find the limit as xx approaches1, i.e., limx1f(x)\lim{x \rightarrow1} f(x)

STEP 2

First, we will try to substitute x=1x=1 into the function and see if it's defined.
f(1)=12111f(1)=\frac{1^{2}-1}{\sqrt{1}-1}

STEP 3

Calculate the value of f(1)f(1).
f(1)=1111f(1)=\frac{1-1}{1-1}

STEP 4

We see that the denominator becomes zero, which means that the function is undefined at x=1x=1. So, we cannot directly substitute x=1x=1 into the function to find the limit. We need to simplify the function first.

STEP 5

We can simplify the function by factoring the numerator.
f(x)=(x1)(x+1)x1f(x)=\frac{(x-1)(x+1)}{\sqrt{x}-1}

STEP 6

We can multiply the denominator and the numerator by the conjugate of the denominator to eliminate the square root.
f(x)=(x1)(x+1)(x+1)(x1)(x+1)f(x)=\frac{(x-1)(x+1)(\sqrt{x}+1)}{(\sqrt{x}-1)(\sqrt{x}+1)}

STEP 7

implify the denominator using the difference of squares formula.
f(x)=(x1)(x+1)(x+1)x1f(x)=\frac{(x-1)(x+1)(\sqrt{x}+1)}{x-1}

STEP 8

Cancel the common factor (x1)(x-1) from the numerator and the denominator.
f(x)=(x+1)(x+1)f(x)=(x+1)(\sqrt{x}+1)

STEP 9

Now, we can substitute x=x= into the simplified function to find the limit.
limxf(x)=(+)(+)\lim{x \rightarrow} f(x) = (+)(\sqrt{}+)

STEP 10

Calculate the limit.
limxf(x)=(2)(2)=4\lim{x \rightarrow} f(x) = (2)(2) =4So, the limit of the function as xx approaches is4.

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord