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Ya, this is part of my homework and I can't seem to solve these.

∫(lnx)[sup]2[/sup]/x dx

[sub]℮[/sub]
∫(1+lnx)[sup]2[/sup]/x dx
[sup]1[/sup]

[sub]2[/sub]
∫(1-cosθ)/(θ-sinθ) dθ
[sup]1[/sup]

℮ is (1+(1/n))[sup]n[/sup] or in arithmethic terms, 2.71828182846
θ is a trigonometric variable

You can't do this by yourself, so you want others to do it for you? That's cheating , but if there's one place that you're going to do it, it's gotta be on SEN

Alright, at school I figured out how to do the first 2 problems. It seems that I had misttod x' by u' and didn't replace it by 1.

Here's the third one:


[sub]2[/sub]
∫(1-cosθ)/(θ-sinθ) dθ
[sup]1[/sup]

θ-sinθ=u
(1-cosθ)dθ=du
dθ=du/(1-cosθ)

u[sub]1[/sub]=1-sin1
u[sub]1[/sub]=0.1585
u[sub]2[/sub]=2-sin2
u[sub]2[/sub]=1.0907

[sub]1.0907[/sub]
∫(1-cosθ)/u du/(1-cosθ)
[sup]0.1585[/sup]

[sub]1.0907[/sub]
∫du/u
[sup]0.1585[/sup]

ln|u| ] {0.1585, 1.0907}

1.928

That's what I say is unecessary to learn, just like most mathematic the teachers have tried to teach me the last 4 years
What is it btw?

Maybe you'd realize why its worth learning if they explained to you what it was. Don't say it isn't worth learning if you don't know what it is.

Calculus is important for rocket science or for any profession that requires mathematics.

We are finding the primitive of the function in the first 2.

In the thrid one, we were looking for the area under the graph.

What's calKOOlus?

We watched Stand and Deliver in math class, sweet movie.

Yesterday I was scrolling around the TV Guide and saw that on HBO Zone they were showing that movie. I only got to see the very end, in which they start questioning wether or not the students cheated, then they take a re-test and the movie ends. I'm looking forward to seeing it from the begining.

We watched that last year, it was like a 5/10. Not to shabby for being a math movie.

This is how I was taught to do it.

Let θ-sinθ = u
Therefore du = (1 - cosθ) dθ

So the integral is substituted with 1/u du, whose integral is naturally ln(|u|) (pun intended).

Plug θ-sinθ back in for u, the final answer is ln(2-sin2) - ln(1-sin1). Tada.

Integration by Substitution

Look a few posts above, and you'll see that I solved the problem step by step in the same way that you are stating.

Also, I wouldn't go to Wikipedia for Calculus references, it has a very general information, and as we know, Calculus is very specific. I got to http://archives.math.utk.edu/visual.calculus/ which has proven to be an excellent source.

My memory is a little off but is that the one with the teacher that nobody likes and a teacher that kicked some punk's ass? And the teacher that kept inviting some foriegn kid to his house?

Ahhh I'm in precal -.-' we're just getting past learning cos/sin FULLY. :/ I only understood that partially.