Find the Laplace transform of f(t) = sin(3t)te^(-2t) and also a piecewise function?

@BentSnowman... I didnt look at all those links, but I did probably five or six. And let me tell you what I saw. I saw each of those questions posted had only one answer. I for one do not select best answer either when I only have one answer to choose from. Its not very competitive when youre the only one answering a question. Im sure Andrew W simply waited to get a second answer (which never came). Sad. You might have been the best answer but you were also the worst, when there is no one else to compete with. I dont see what youre complaining about. I would also wait to get a second answer, or more, before selecting BA... and even then I would only select BA IF I actually had a satisfactory answer to the question. You could wait to get that second answer (or any decent answer for that matter) right up to the very end, and then the question goes up for vote automatically. Its perfectly understandable. The same exact scenario has played out with questions Ive asked. Nine times out of ten I wish I could simply delete my question for the shitty answers I get.

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ℒ{ t e^(-2t) sin(3t) } =

-d/ds ℒ{ e^(-2t) sin(3t) } =

-d/ds ℒ{ sin(3t) }(s+2) =

-d/ds (3 / ((s+2)² + 9)) =

-d/ds (3 / (s² + 4s + 13) =

3(2s + 4) / (s² + 4s + 13)² =

(6s + 12) / (s² + 4s + 13)²

For the second one.

f(t) = t - t u₁(t)

ℒ{ t - t u₁(t) } =

1/s² + d/ds ℒ{ u₁(t) }

1/s² + d/ds e^(-s)/s

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Well, if BentSnowman is correct about this then I will learn the lesson quick. I will block all people who play me at that game, and I dont ever help them again. I guess we will find out. I guess the question Andrew needs to ask himself is whether or not he wants to alienate all the people who could help him with laplace transforms, since there are so many of us familiar with this kind of math its not like he'd have a lot to lose.

@Andrew, call it a human failing if you wish, but we all implicitly or explicitly EXPECT to be rewarded for our efforts. No human being is completely selfless. Its basic capitalism. We do a service, you pay us for that service. Fair is fair. We all agree to play this "game" by participating in the forum. Youre the one expecting something for nothing, so dont talk about virtue.

I remember you, you are the guy who never picks a best answer or even indicates in any way that the answers you get even helped you. No thanks!

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No, I looked at your history, not just one question. I do not care about points, I care to know though if the effort I put into answering a question actually helped someone (this can be communicated by selecting best answer, or by followup comment from an asker). Your accusation of me caring about percentages and points was wishful, you must know that.

Show me one instance where you chose a best answer other than just now:

answers.yahoo.com/question/index?qid=20 130502202519AAuwf6x

answers.yahoo.com/question/index?qid=20 130503141720AAS7NeE

answers.yahoo.com/question/index?qid=20 130723203508AAtCa0E

answers.yahoo.com/question/index?qid=20 121109172129AAmDzck

answers.yahoo.com/question/index?qid=20 121102174959AATuI63

answers.yahoo.com/question/index?qid=20 121031162123AAZ6Guf

answers.yahoo.com/question/index?qid=20 121030172705AA8oosw

answers.yahoo.com/question/index?qid=20 121014173748AAhIF6R

answers.yahoo.com/question/index?qid=20 130723203508AAtCa0E

answers.yahoo.com/question/index?qid=20 140227165633AA9GC7h

answers.yahoo.com/question/index?qid=20 140213223947AA12OSv

answers.yahoo.com/question/index?qid=20 140128222513AAOPmvB

answers.yahoo.com/question/index?qid=20 140116152051AAo1Klm

You might want to choose a different hobby other than lying, it isn't working out as well as you hoped. I see zero instances of you choosing an answer or otherwise providing any kind of feedback. Ask any frequenter of Y!A math section, what we really care about is helping someone learn, not the points. Not sure what it says I am top contributor for currently, but it is either math or etiquette. It is basic etiquette on this site to show appreciation for an answer by choosing a best answer or otherwise indicating the answers were helpful (if applicable). I guess you just do not like being told you did not do everything perfect. I would have dropped it, but I didn't like seeing you try and lie just now. Not, it is not that "big of a deal," but I have ever right to be annoyed with someone thinking they can defend themselves with a lie to me then call me an asshole lol.

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Cogitoergocogitosum, that is a salient point! However, glancing at his other questions I can post as many links to questions with more than one answer as well.

By the way, if you want a second answer, I see this guy knows quite well how to add "updates" to questions. He can make it known or otherwise let people know what he is still confused about. Playing the waiting game can be sad, but it is also your own doing.

I am complaining about him lying and calling me an asshole to what I originally said, which was just one sentence pointing something out that he does and why I am not enthused to answer his question.