How do I evaluate a double integral with a trigonometric function?

In summary, the conversation revolves around evaluating a given integral with the order of integration reversed. The limits for the integral are discussed and the use of integration by parts is considered. However, it is determined that the integral cannot be solved using integration by parts due to the nature of the function. Alternative methods, such as using a table of integrals, are suggested for solving the integral.
  • #1
math_04
23
0

Homework Statement



Given the integral shown (in attachment), make a sketch of the region of integration, express the integral with the order of integration reversed and evaluate the integral after reversing the order of integration

Homework Equations





The Attempt at a Solution



So i got the limits as y<= x <= 1 and 0 <= y <= 1

But for the function y^2 sin xy dxdy, how should i integrate that. Integration by parts would not work because v= 0 so the whole integral becomes 0. Should i just read it off the table of integrals. if i do that, the integral becomes -y^2cosxy dx rite?

Thanks
 

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  • #2
oh no, attachment pending approval. not again haha.
 
  • #3
As said before, if you want quick replies, just host it on imageshack.us or some other image-hosting web service.
 
  • #4
hahahaha~~~~~~~~

but why do they need to be approved?
 
  • #5
You seem to have done the same thing you did with the previous problem: your "inner" integral goes from x to 1 while the shaded area in your picture is below the line y= x.
 
  • #6
ohhh my god ur rite hallsofIvy thanks.

Alright, so the limits change but how do u evaluate that integral. Cant do it by parts cause of the reasons i mentioned.
 

Related to How do I evaluate a double integral with a trigonometric function?

1. What is the purpose of evaluating a double integral?

Evaluating a double integral allows us to find the volume under a surface in 3-dimensional space. It is a useful tool in many fields of science, including physics, engineering, and mathematics.

2. How do you set up a double integral?

To set up a double integral, we first need to identify the region of integration and the function to be integrated. We then choose the order of integration, either by integrating with respect to one variable first and then the other, or by reversing the order. Finally, we determine the limits of integration for each variable based on the region of integration.

3. What is the difference between a definite and indefinite double integral?

A definite double integral has specific limits of integration and will result in a single numerical value. An indefinite double integral has no limits of integration and will result in a function of two variables.

4. How do you evaluate a double integral?

To evaluate a double integral, we can use various methods such as iterated integration, changing the order of integration, or using polar or spherical coordinates. It is important to carefully choose the order of integration and the limits of integration to make the integration process easier.

5. What are some applications of double integrals in science?

Double integrals have various applications in science, including calculating mass and center of mass, finding the flux of a vector field, and determining the volume of a solid with a varying density. They are also used in statistics to calculate joint probabilities and in economics to determine the total value of a function over a given region.

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