Anti-derivative of a trig equation

  • Thread starter togame
  • Start date
  • Tags
    Trig
In summary, to find the anti-derivative of the given equation, \int x(sin^2(3x)cos(3x))dx, integrate by parts with u = x and dv = sin^2(3x)cos(3x)dx. Then use the substitution y = sin(3x) to solve for the integral of sin^2(3x)cos(3x).
  • #1
togame
18
0

Homework Statement


I just need to find the anti-derivative of this equation:
[itex]\int x(sin^2(3x)cos(3x))dx[/itex]



Homework Equations


[itex]sin^2(x)+cos^2(x)=1[/itex]


The Attempt at a Solution


I'm not really sure where to start here. I tried to do a substitution first but couldn't make it work. So then I tried to put sin^2 in terms of cos^2 but that didn't seem to help me out any more. Anyone have an idea of how to tackle this problem? Thanks in advance!
 
Physics news on Phys.org
  • #2
togame said:

Homework Statement


I just need to find the anti-derivative of this equation:
[itex]\int x(sin^2(3x)cos(3x))dx[/itex]



Homework Equations


[itex]sin^2(x)+cos^2(x)=1[/itex]


The Attempt at a Solution


I'm not really sure where to start here. I tried to do a substitution first but couldn't make it work. So then I tried to put sin^2 in terms of cos^2 but that didn't seem to help me out any more. Anyone have an idea of how to tackle this problem? Thanks in advance!

Integrate by parts, with u = x, dv = [itex]\sin^2(3x)\cos(3x)dx[/itex].

To integrate [itex]\sin^2(3x)\cos(3x)dx[/itex], use the substitution [itex]y = \sin(3x)[/itex]
 
  • #3
Curious3141 said:
Integrate by parts, with u = x, dv = [itex]\sin^2(3x)\cos(3x)dx[/itex].

To integrate [itex]\sin^2(3x)\cos(3x)dx[/itex], use the substitution [itex]y = \sin(3x)[/itex]

Thank you very much. I didn't see the ability to do another substitution right off hand.
 

Related to Anti-derivative of a trig equation

What is an anti-derivative of a trig equation?

An anti-derivative of a trigonometric equation is a function whose derivative is equal to the original trigonometric equation. It is also known as an indefinite integral.

How do you find the anti-derivative of a trig equation?

To find the anti-derivative of a trigonometric equation, you can use the basic integration rules for trigonometric functions, such as the power rule, substitution, and integration by parts.

What are the common trigonometric functions used in anti-derivatives?

The most common trigonometric functions used in anti-derivatives are sine, cosine, tangent, cotangent, secant, and cosecant. These functions are used in various combinations and forms to find the anti-derivative of a trigonometric equation.

Why is the anti-derivative of a trig equation important?

The anti-derivative of a trigonometric equation is important because it helps in solving many real-world problems that involve trigonometric functions. It is also a fundamental concept in calculus and is used extensively in higher-level mathematics and science courses.

Can every trigonometric equation have an anti-derivative?

No, not every trigonometric equation has an anti-derivative. Some trigonometric equations are not integrable, meaning they do not have a closed-form solution. In such cases, numerical methods or approximation techniques are used to find the anti-derivative.

Similar threads

  • Calculus and Beyond Homework Help
Replies
5
Views
601
  • Calculus and Beyond Homework Help
Replies
11
Views
725
  • Calculus and Beyond Homework Help
Replies
1
Views
529
  • Calculus and Beyond Homework Help
Replies
3
Views
619
  • Calculus and Beyond Homework Help
Replies
2
Views
863
  • Calculus and Beyond Homework Help
Replies
11
Views
983
  • Calculus and Beyond Homework Help
Replies
6
Views
601
  • Calculus and Beyond Homework Help
Replies
18
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
864
  • Calculus and Beyond Homework Help
Replies
22
Views
1K
Back
Top