xkcd: integration by parts

Came across this xkcd comic:

No, it should be integral of v du that you want to see if it is easier.

For the record, I haven't need to do this once after high school.

u-substitution and by-part are the only 2 general methods to evaluate integrals. People came up with all sorts of techniques to integrate expressions for certain patterns... and therefore you got the table of integrals on the back of your calculus book.

omg, now you can do just about everything with calculus on the web. See this powerful Wolfram site: http://www.wolframalpha.com/examples/Calculus.html

Now, should we let kids use calculators on their test? What if they fire up their phones online and cheat that way?

Letters containing Ricin

Yikes, letters of poison sent to government officials right after an act of terrorism. This is basically a repeat of 9/11 pattern a dozen years ago. See here for a reminder of the details.

President Obama got one of these. Glad he does not need to open his own letters. See news details here. However, what I don't understand is this. How come no news report tells me what the letters say?

This time it is ricin. There are so many deadly plants and things out there, and people thought about this as chemical weapon. Poison is supposed to be banned in some national treaties that nobody follows anyway. Ok it is harsh to kill with chemical weapons of mass destruction. Is it not harsh to kill somebody with a machine gun?

I hope we soon get to the bottom of the poison letters and to the Boston bombing.

Boston Explosion

OMG, terrorism strikes America again! This is the biggest act of terror on America after 9/11 at the Boston Marathon. How sad is this... At this point no one is responsible yet. Don't jump to conclusions too quickly. It may not be the al Queada, it may be some mad man right here in America.

I do believe people will eventually find out who did this.

I frequently check the news lately. Is North Korea actually sending nukes at someone? at its intended location? Alas, there are actually many bombing and killings around the world around this time too. This news is in boldface big font because it is occurring in America. and there is an earthquake killing dozens at the Iran-Pakistan. We cannot prevent natural disasters.. but human disasters... come on, what gain do you get when you kill a few innocent marathon athletes and their supporters? The guy is got to be mad at something... or insane. or want to revenge America for something. That 8 year old and other victims didn't harm you, you hear? Killing the innocents does not solve your problems!

The CTA has this sign all over the place: if you see something say something.

Unfortunately, hundreds of people at the marathon still wasn't able to see something, say something, and prevent such thing. We are so helpless against the next disaster.

Google honors Euler

What a pleasure to see Google honors my favorite mathematician Euler:

See more about Euler here. He is one of the greatest mathematicians ever known. Few people has a number named after him: e. That's right, the base of the natural logarithm. Your calculator has an e^x button. You must be dozing in calculus or had a professor who can't speak English if you don't know what's so natural about the natural logarithm. (Yes, d/dx e^x = e^x) It is invincible for differentiation.

But wait there's more... that Euler formula in the lower-right corner connects e, i, π, and also 0 and 1 together. Such relationship is a beauty in the eyes of the mathematicians. I have a great book on this fabulous formula (I wish I understand all of it).

See that bridge over there in the google image? It is the Seven Bridges of Königsberg problem that opens a new chapter in math: topology.

That V - E + F = 2 is also known as Euler's formula for shapes and stuff.

Rick Warren's son commits suicide

Rick Warren's son committed suicide, apparently because of depression.

You may have heard of Rick Warren's famous book "The Purpose Driven Life". Millions of copies sold. I've read this book myself. This book is well written in clear language, highlighting the cash cow important verse Jeremiah 29:11

"For I know the plans I have for you,” declares the Lord, “plans to prosper you and not to harm you, plans to give you hope and a future."

I can see how this book may even transform lives for it supposedly have give the hopeless hopes, and the purposeless with some purpose. I certainly admire people who can sell millions of books...

How many people actually zoom out of the verse and read just the chapter? The LORD is talking to those who were taken exile... not to you.

Yikes, Rick Warren's own son was in depression, despite having a loving family, prayers, and the best medical personnels and counselors available... Matt still can't climb out of the depression. Some depression perhaps can trait back to a cause... such as Miss Right decides to go with a lessor being, friends betray you, couldn't get to the school/job you want, or growing up without loving parents... alas sometimes we can't trace to the source and resolve... I guess depression can be something beyond what current medicines can fix... but yikes how much are the not-so-helpful doctors and counselors charging Warren? That bill can cause someone who don't make as much money right into depression.

Not even faith can help him... now that's depressing.

Read the next verse in Jeremiah, "Then you will call on me and come and pray to me, and I will listen to you. " I am sure they did. How come the LORD doesn't actually step in to help?

Now, here is a another tough theological question... is Matt going to heaven? He has violated "thou shalt not kill (yourself)"

Who understands the pain Matt has to go through? Who understand the pains that some people with horrible diseases who wants to go to Jack Kevorkian-style suicide go through? This is a tough question.