Math Problem Statement

Consider the function f(x) = sqrt(x + 99). Find the linearization of f at a = 1, and use it to approximate sqrt(99), rounded to six decimal places.

Solution

Let's solve the problem in two parts, as outlined in the image:

Part (a): Find the linearization L(x)L(x) of the function f(x)=x+99f(x) = \sqrt{x + 99} at a=1a = 1.

The linearization of a function f(x)f(x) at a=1a = 1 is given by the formula: L(x)=f(a)+f(a)(xa)L(x) = f(a) + f'(a)(x - a)

Step 1: Calculate f(a)f(a)

Since a=1a = 1 and f(x)=x+99f(x) = \sqrt{x + 99}, we calculate f(1)f(1): f(1)=1+99=100=10f(1) = \sqrt{1 + 99} = \sqrt{100} = 10

Step 2: Find f(x)f'(x) (the derivative of f(x)f(x))

Using the chain rule, the derivative of f(x)=x+99f(x) = \sqrt{x + 99} is: f(x)=12x+99f'(x) = \frac{1}{2\sqrt{x + 99}}

Step 3: Evaluate f(a)f'(a)

Now, substitute a=1a = 1 into f(x)f'(x): f(1)=121+99=12100=120f'(1) = \frac{1}{2\sqrt{1 + 99}} = \frac{1}{2\sqrt{100}} = \frac{1}{20}

Step 4: Write the linearization L(x)L(x)

Substitute the values of f(1)f(1) and f(1)f'(1) into the linearization formula: L(x)=10+120(x1)L(x) = 10 + \frac{1}{20}(x - 1) So the linearization is: L(x)=10+120(x1)L(x) = 10 + \frac{1}{20}(x - 1)

Part (b): Use the linearization to approximate 99\sqrt{99}

We want to approximate 99\sqrt{99} using the linearization. Notice that 99\sqrt{99} is f(0)f(0) because f(x)=x+99f(x) = \sqrt{x + 99}, and if x=0x = 0, then f(0)=99f(0) = \sqrt{99}.

So, we substitute x=0x = 0 into the linearization L(x)L(x): L(0)=10+120(01)=10+120(1)=10120=100.05=9.95L(0) = 10 + \frac{1}{20}(0 - 1) = 10 + \frac{1}{20}(-1) = 10 - \frac{1}{20} = 10 - 0.05 = 9.95

Thus, using the linearization, the approximation for 99\sqrt{99} is: 999.950000\sqrt{99} \approx 9.950000

Final Answer:

  • (a) The linearization is L(x)=10+120(x1)L(x) = 10 + \frac{1}{20}(x - 1).
  • (b) The approximation for 99\sqrt{99} is approximately 9.9500009.950000, rounded to six decimal places.

Would you like more details on any part of this solution, or do you have any further questions?

Here are 5 related questions to explore:

  1. How does linearization provide an approximation for functions near a point?
  2. What is the general formula for the linearization of a function?
  3. How accurate is the approximation of 99\sqrt{99} compared to the actual value?
  4. Can linearization be used for any type of function?
  5. What are the limitations of using linearization for approximations?

Tip: The accuracy of linearization depends on how close xx is to the point of linearization aa. The closer xx is to aa, the more accurate the approximation.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linearization
Derivatives
Approximations

Formulas

L(x) = f(a) + f'(a)(x - a)
f'(x) = 1 / (2 * sqrt(x + 99))

Theorems

Linear Approximation Formula

Suitable Grade Level

Undergraduate Calculus