Math Is Fun Forum

Prakash Panneer

Member

Registered: 2006-06-01

Posts: 110

Integration- Please help me

[img]C:\Documents and Settings\Prakash\Desktop\Image.JPG[/img]

Find the integral of f(x) whose limit is 0 to 2.

The graph is supposed to look like two semicircles starting at the origin and ending at 6.

Please help me.

Thanks in advance.

Last edited by Prakash Panneer (2008-12-05 02:59:05)

---

Letter, number, arts and science
of living kinds, both are the eyes.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,422

Re: Integration- Please help me

Prakash Panneer,
The [img],[/img] tags can be used only for images in existing websites.
For images on your PC, use Image Upload which can be done by editing your post.
(Limits: 20 images per post, each image must be less than 1501x1501 pixels and 100 KB)
This is how the image would appear.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: Integration- Please help me

Integrate this geometrically.  Remember, the integral is the "area under the curve".

---

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

Prakash Panneer

Member

Registered: 2006-06-01

Posts: 110

Re: Integration- Please help me

Do we have to find the equation of the two semi circles then add them?

or do we need enough to find the first semi circle based on the limit as 0 to 2?

---

Letter, number, arts and science
of living kinds, both are the eyes.

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Integration- Please help me

You don't need to know the equation of the second semicircle, since it doesn't appear in the region you're integrating.

The equation of the first would be y = -√[x(2-x)]. Integrating that between 0 and 2 will give you the answer.

However, this question doesn't need integration at all.
You know that the curve is a semicircle, so you can find the area underneath it directly.
It has radius 1, so the answer is -π/2 (the semicircle is underneath the x-axis so the answer must be negative)

---

Why did the vector cross the road?
It wanted to be normal.

Prakash Panneer

Member

Registered: 2006-06-01

Posts: 110

Re: Integration- Please help me

Thanks a lot

---

Letter, number, arts and science
of living kinds, both are the eyes.