Assume that f(x)=ln(1+x) is the given function and that Pn represents the nth Taylor Polynomial centered at x=0. Find the least integer n for which Pn(0.2) approximates ln(1.2) to within 0.01.

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Answer:

the least integer for n is 2

Step-by-step explanation:

We are given;

f(x) = ln(1+x)

centered at x=0

Pn(0.2)

Error < 0.01

We will use the format;

[[Max(f^(n+1) (c))]/(n + 1)!] × 0.2^(n+1) < 0.01

So;

f(x) = ln(1+x)

First derivative: f'(x) = 1/(x + 1) < 0! = 1

2nd derivative: f"(x) = -1/(x + 1)² < 1! = 1

3rd derivative: f"'(x) = 2/(x + 1)³ < 2! = 2

4th derivative: f""(x) = -6/(x + 1)⁴ < 3! = 6

This follows that;

Max|f^(n+1) (c)| < n!

Thus, error is;

(n!/(n + 1)!) × 0.2^(n + 1) < 0.01

This gives;

(1/(n + 1)) × 0.2^(n + 1) < 0.01

Let's try n = 1

(1/(1 + 1)) × 0.2^(1 + 1) = 0.02

This is greater than 0.01 and so it will not work.

Let's try n = 2

(1/(2 + 1)) × 0.2^(2 + 1) = 0.00267

This is less than 0.01.

So,the least integer for n is 2

In this exercise we have to use the knowledge of Taylor Polynomial to calculate the requested function, this way we will have;

the least integer for n is 2    

The function given in this exercise corresponds to:

[tex]f(x) = ln(1+x)[/tex]

knowing that the x point will be centered on:

[tex]x=0\\Pn(0,2)\\Error < 0.01[/tex]

By rewriting the equation we have to:

[tex][[Max(f^{(n+1)} (c))]/(n + 1)!] *0.2^{(n+1)} < 0.01[/tex]

So doing the derivatives related to the first function given in the exercise we have to:

[tex]f(x) = ln(1+x)[/tex]

  • First derivative: [tex]f'(x) = 1/(x + 1) < 0! = 1[/tex]
  • 2nd derivative: [tex]f"(x) = -1/(x + 1)^2 < 1! = 1[/tex]
  • 3rd derivative: [tex]f"'(x) = 2/(x + 1)^3 < 2! = 2[/tex]
  • 4th derivative: [tex]f""(x) = -6/(x + 1)^4 < 3! = 6[/tex]

Following this we have to:

[tex]Max|f^{(n+1)} (c)| < n![/tex]

Thus, error is;

[tex](n!/(n + 1)!) * 0.2^{(n + 1)} < 0.01[/tex]

[tex](1/(n + 1))* 0.2^{(n + 1)} < 0.01[/tex]  

Let's try n = 1

[tex](1/(1 + 1)) *0.2^{(1 + 1)} = 0.02[/tex]

This is greater than 0.01 and so it will not work. Let's try n = 2

[tex](1/(2 + 1)) * 0.2^{(2 + 1)} = 0.00267[/tex]

This is less than 0.01. So,the least integer for n is 2.

See more about Taylor polynomial at brainly.com/question/23842376