[tex]\int x^2sin\pixdx[\math]

why doesnt this latex thing work for me????

i dont know how to integrate x^2sin(pi)xdx

Printable View

- Jan 29th 2007, 01:58 PMjephIntegration by parts
[tex]\int x^2sin\pixdx[\math]

why doesnt this latex thing work for me????

i dont know how to integrate x^2sin(pi)xdx - Jan 29th 2007, 03:27 PMtopsquark
- Jan 29th 2007, 05:20 PMjeph
- Jan 29th 2007, 07:03 PMtopsquark
- Jan 29th 2007, 07:15 PMThePerfectHacker
A useful rule to remember....

Let be an antiderivative of .

Then, ( ),

Meaning whenever you have a linear function (of the form ax+b) you just take the coefficient with the "x" (the slope of line) and invert it.

For example,

Since this is a linear expression inside,

.

You can use the rule I told you.

Just find the anti-derivative the regular way,

But of course this answer is wrong, you need to invert the slope.

Thus,

Now let us find,

Note is a linear function in the special form we had above because is just a number in front.

Thus, to find the integral you just find the integral of sine which is -cosine and then invert the slope.

Thus,

.

Learn, this rule, it saves much time.