Calculus Homework

profilemirananwar
Hw21.pdf

Miran Anwar, mth 235 ss21 1: Hw21-6.2-BVP-FS. Due: 04/26/2021 at 11:00pm EDT.

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 1. (10 points)

Consider the function f defined on the interval [−5,5] as follows,

f (x) =

{ −5, x ∈ [−5,0),

5, x ∈ [0,5].

Denote by fF the Fourier series expansion of f on [−5,5],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

Comments on the graph below: (Optional, worth no points)

• The first time running it may take a few minutes to load. • The graph is interactive, it allows you to see your solutions. • You type the answers for a0, an = a(n), and bn = b(n) inside the graph. • Use the key Tab to enter the values inside the graph; do not use Enter; if you do, the graph resets

itself. • You can move the slider for the Fourier approximation N. • Type math as in Webwork. Use * for multiplication. • You can use parenthesis in the graph, ( ), but not brackets, [ ]. • Recall, the graph part of the problem is worth no points.

1

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 2. (10 points)

Consider the function f defined on the interval [−5,5] as follows,

f (x) =

{ −1, x ∈ [−5,0),

2, x ∈ [0,5].

Denote by fF the Fourier series expansion of f on [−5,5], 1

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 3. (10 points)

Consider the function f defined on the interval [−3,3] as follows,

f (x) =

  −

4 3

x, x ∈ [−3,0),

4 3

x, x ∈ [0,3].

Denote by fF the Fourier series expansion of f on [−3,3],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

Comments on the graph below: (Optional, worth no points)

• The first time running it may take a few minutes to load. • The graph is interactive, it allows you to see your solutions. • You type the answers for a0, an = a(n), and bn = b(n) inside the graph. • Use the key Tab to enter the values inside the graph; do not use Enter; if you do, the graph resets

itself. • You can move the slider for the Fourier approximation N. • Type math as in Webwork. Use * for multiplication. • You can use parenthesis in the graph, ( ), but not brackets, [ ]. • Recall, the graph part of the problem is worth no points.

1

2

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 4. (10 points)

Consider the function f defined on the interval [−3,3] as follows,

f (x) = 2 3

x.

Denote by fF the Fourier series expansion of f on [−3,3],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 5. (10 points)

Consider the function f defined on the interval [−3,3] as follows,

f (x) =

 

0, x ∈ [−3,0), 1 3

x, x ∈ [0,3].

Denote by fF the Fourier series expansion of f on [−3,3],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

Comments on the graph below: (Optional, worth no points) 3

• The first time running it may take a few minutes to load. • The graph is interactive, it allows you to see your solutions. • You type the answers for a0, an = a(n), and bn = b(n) inside the graph. • Use the key Tab to enter the values inside the graph; do not use Enter; if you do, the graph resets

itself. • You can move the slider for the Fourier approximation N. • Type math as in Webwork. Use * for multiplication. • You can use parenthesis in the graph, ( ), but not brackets, [ ]. • Recall, the graph part of the problem is worth no points.

1

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 6. (10 points)

Consider the function f defined on the interval [−5,5] as follows,

f (x) =

 

0, x ∈ [−5,0),

3 (

1− x 5

) , x ∈ [0,5].

Denote by fF the Fourier series expansion of f on [−5,5],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 7. (10 points)

Given the function f (x) = 5x + 2 defined on the interval (0,2], denote by fo the odd extension on [−2,2] of f .

Find foF , the Fourier series expansion of fo,

foF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] ,

that is, find the coefficients a0, an, and bn, with n > 1. 4

a0 =

an =

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 8. (10 points)

Given the function f (x) = 2x + 1 defined on the interval (0,5], denote by fe the even extension on [−5,5] of f .

Find feF , the Fourier series expansion of fe,

feF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] ,

that is, find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 9. (0 points)

Consider the function f defined on the interval [−3,3] as follows,

f (x) =

 

4 (

1 + x 3

) , x ∈ [−3,0),

4 (

1− x 3

) , x ∈ [0,3].

Denote by fF the Fourier series expansion of f on [−3,3],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an = 5

bn =

See in LN, § 6.2, See Examples 6.2.3-6.2.7. 10. (0 points)

Consider the function f defined on the interval [−5,5] as follows,

f (x) =

  −1 (

1 + x 5

) , x ∈ [−5,0),

1 (

1− x 5

) , x ∈ [0,5].

Denote by fF the Fourier series expansion of f on [−5,5],

fF (x) = a0 2 +

∑ n=1

[ an cos

(nπx L

) + bn sin

(nπx L

)] .

Find the coefficients a0, an, and bn, with n > 1.

a0 =

an =

bn =

Generated by c©WeBWorK, http://webwork.maa.org, Mathematical Association of America

6