Composition of trigonometric functions, mean value theorem

In summary, the conversation discusses using the Mean Value Theorem (MVT) to show that cos(cos x) is a contraction. The equation | d/dx (cos(cos x)) | = | sin(cos x) sin(x) | < sin 1 < 1 is used to solve the problem. The question is raised about how to know the range of values for sin(cos(x)) given that -1<=cos(x)<=1.
  • #1
zbot1
2
0

Homework Statement



how to show using MVT that cos(cos x) is a contraction.

Homework Equations



| d/dx (cos(cos x)) | = | sin(cos x) sin(x) | < sin 1 < 1

The Attempt at a Solution



Using that relation, the original problem is easily solved. My question is, how do we know:

| sin(cos x) sin(x) | < sin 1 ?

-zbot1
 
Physics news on Phys.org
  • #2
zbot1 said:

Homework Statement



how to show using MVT that cos(cos x) is a contraction.

Homework Equations



| d/dx (cos(cos x)) | = | sin(cos x) sin(x) | < sin 1 < 1

The Attempt at a Solution



Using that relation, the original problem is easily solved. My question is, how do we know:

| sin(cos x) sin(x) | < sin 1 ?

-zbot1

-1<=cos(x)<=1. What does that make the range of values for sin(cos(x))?
 
  • #3
Thanks!
 

Related to Composition of trigonometric functions, mean value theorem

1. What is the composition of trigonometric functions?

The composition of trigonometric functions is the process of combining two or more trigonometric functions to form a new function. This is done by plugging one function into another, where the output of the first function becomes the input of the second function.

2. Can trigonometric functions be composed with non-trigonometric functions?

Yes, trigonometric functions can be composed with non-trigonometric functions. However, the result may not always be a trigonometric function.

3. What is the mean value theorem?

The mean value theorem states that for a differentiable function on an interval, there exists at least one point on the interval where the instantaneous rate of change (derivative) is equal to the average rate of change of the function over that interval.

4. How is the mean value theorem related to trigonometric functions?

The mean value theorem can be applied to trigonometric functions to find the average rate of change over a given interval. This can be useful in finding the maximum and minimum values of a trigonometric function.

5. Can the mean value theorem be used to prove the existence of solutions to trigonometric equations?

Yes, the mean value theorem can be used to prove the existence of solutions to trigonometric equations. This is because it guarantees the existence of at least one point where the derivative of the function is equal to the average rate of change, which can help in finding solutions to equations.

Similar threads

  • Calculus and Beyond Homework Help
Replies
1
Views
309
  • Calculus and Beyond Homework Help
Replies
3
Views
619
  • Calculus and Beyond Homework Help
Replies
6
Views
459
  • Calculus and Beyond Homework Help
Replies
1
Views
793
  • Calculus and Beyond Homework Help
Replies
2
Views
863
  • Calculus and Beyond Homework Help
Replies
9
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
864
  • Calculus and Beyond Homework Help
Replies
5
Views
989
  • Calculus and Beyond Homework Help
Replies
18
Views
1K
Back
Top