Derivative of A Trigonometric Function

Click For Summary

Homework Help Overview

The discussion centers around finding the derivative of the function f(x) = 1/4 sin^2 2x, which involves trigonometric functions and differentiation techniques.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the differentiation process, with one individual attempting to apply the chain rule and product rule. There is a question regarding a discrepancy between the participant's answer and the textbook's answer, prompting a review of the differentiation steps.

Discussion Status

Some guidance has been offered regarding a potential oversight in the differentiation process, specifically the factor of 2 that may have been missed. The discussion reflects an ongoing exploration of the differentiation steps without reaching a final consensus.

Contextual Notes

Participants are working under the constraints of homework guidelines, which may limit the extent of assistance provided. There is an acknowledgment of a potential misunderstanding in the application of differentiation rules.

Bashyboy
Messages
1,419
Reaction score
5

Homework Statement


Find the derivative of f(x) = 1/4 sin^2 2x


Homework Equations





The Attempt at a Solution



f'(x) =1/4(sin 2x)^2

f'(x) = 1/4*2(sin 2x)(cos 2x)

f'(x) = 1/4(sin 4x)

That is my answer to the problem, but the book has it as f'(x) = 1/2(sin 4x)
What did I do wrong?
 
Physics news on Phys.org
you forgot the factor of 2 when you differentiate (sin(2x))
 
Oh, yes, thank you.
 
Bashyboy said:

Homework Statement


Find the derivative of f(x) = 1/4 sin^2 2x

The Attempt at a Solution


f'(x) =1/4(sin 2x)^2
(Above) This is f(x), not f'(x).
Bashyboy said:
f'(x) = 1/4*2(sin 2x)(cos 2x)

f'(x) = 1/4(sin 4x)

That is my answer to the problem, but the book has it as f'(x) = 1/2(sin 4x)
What did I do wrong?
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
5
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K