Two Cans & String

{ "thread_id": "1829", "posts": [ { "id": "67338", "time": "1302581562", "html": "If you have math problems, post here.", "user": "beary605" }, { "id": "67834", "time": "1302647709", "html": "Not really a problem but just a question.<br />\n<br />\nExplain how Sine^-1 turns sine into an angle, usually theta :P", "user": "sporeinsanity" }, { "id": "67849", "time": "1302649291", "html": "Arcsine undoes Sine. The information you gather from a triangle is the Sine of ABC, which is not useful in finding the angle measurement. We can undo Sine though with Arcsine, just like how the sqrt(x²) == x.<br />\n<br />\nAt least, I think that's how it is explained.", "user": "sophrosyne" }, { "id": "67983", "time": "1302659818", "html": "This might be a bit vague, but here goes.<br />\n<br />\nGiven: (x+3)^2<br />\n<br />\nFind: f(x+h)<br />\n<br />\nAny help?", "user": "burritofamine" }, { "id": "67984", "time": "1302660350", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/sophrosyne/\">Sophrosyne</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">Arcsine undoes Sine. The information you gather from a triangle is the Sine of ABC, which is not useful in finding the angle measurement. We can undo Sine though with Arcsine, just like how the sqrt(x²) == x.<br />\n<br />\nAt least, I think that's how it is explained.</div></div><br />\n<br />\n... but how does putting sine under a sign that means "basically" to give the reciprocal... how does that worK?", "user": "sporeinsanity" }, { "id": "67985", "time": "1302660581", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/burritofamine/\">Burrito Famine</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">This might be a bit vague, but here goes.<br />\n<br />\nGiven: (x+3)^2<br />\n<br />\nFind: f(x+h)<br />\n<br />\nAny help?</div></div>Are you not given the original function f? I'm a little lost as to what is being asked.", "user": "hydrogen777" }, { "id": "67988", "time": "1302660951", "html": "I'm only asking why you get the angle that creates the ratio of Sine when you press Sin^-1 Yes, I understand what ArcSine is, but how does getting a reciprocal reproduce the angle?", "user": "sporeinsanity" }, { "id": "67992", "time": "1302661175", "html": "Ah, it's not a reciprocal. The symbol is a bit misleading. The ^-1 simply means that it's the inverse function, not that it's the multiplicative inverse (reciprocal).<br />\n<br />\nEdit: In other words, sin^-1 is just a function designed to return the angle that yields whatever sine value is given it.", "user": "hydrogen777" }, { "id": "67993", "time": "1302661212", "html": "The ^-1 doesn't actually mean the reciprocal - it's notational shorthand for arcsin.<br />\n<br />\nIn the same way that x^-1(x(a)) = a, sin^-1(sin(a)) = a.<br />\n<br />\nAlso, to the function question:<br />\nIf you mean that f(x) = (x + 3)², then f(x+h) = ((x+h)+3)². Everywhere you see x in the original function, replace it with (x+h).", "user": "fwip" }, { "id": "67994", "time": "1302661239", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/hydrogen777/\">Hydrogen777</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">Ah, it's not a reciprocal. The symbol is a bit misleading. The ^-1 simply means that it's the inverse function, not that it's the multiplicative inverse (reciprocal).</div></div><br />\nso what's an inverse function?", "user": "sporeinsanity" }, { "id": "67999", "time": "1302661406", "html": "It is a function that "undoes" a corresponding function. The inverse of the function "f(x) = x + 1" for example would be "f^-1(x) = x - 1".", "user": "hydrogen777" }, { "id": "68028", "time": "1302662770", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/hydrogen777/\">Hydrogen777</a> said:</div><div style=\"border:1px solid #888; padding:20px;\"><div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/burritofamine/\">Burrito Famine</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">This might be a bit vague, but here goes.<br />\n<br />\nGiven: (x+3)^2<br />\n<br />\nFind: f(x+h)<br />\n<br />\nAny help?</div></div>Are you not given the original function f? I'm a little lost as to what is being asked.</div></div><br />\n<br />\nSo am I. But its on my homework and I haven't the slightest clue on what to do. I don't even know what it is asking. Oh well...", "user": "burritofamine" }, { "id": "68100", "time": "1302665943", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/burritofamine/\">Burrito Famine</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">This might be a bit vague, but here goes.<br />\n<br />\nGiven: (x+3)^2<br />\n<br />\nFind: f(x+h)<br />\n<br />\nAny help?</div></div><br />\nI dunno. If f(x)=(x+3)², then f(x+h) would be:<br />\nf(x+h)=[(x+h)+3]²<br />\nf(x+h)=(x+h+3)²<br />\nf(x+h)=x²+h²+9+2hx+6x+6h<br />\nf(x+h)=x²+(2h+6)x+h²+6h+9", "user": "beary605" }, { "id": "68344", "time": "1302705542", "html": "Thank you Beary! You are a cool cat.", "user": "burritofamine" }, { "id": "68492", "time": "1302712778", "html": "If this is just a derivative, when f(x)=(x+3)^2, f'(x) = 2(x+3). Easy :)", "user": "marymansour" }, { "id": "68624", "time": "1302726730", "html": "Hoooly shit, I'm so fucked if there is no one here to help me, like now!", "user": "ywkbme" }, { "id": "68625", "time": "1302726806", "html": "What are you talking about?", "user": "verum" }, { "id": "68626", "time": "1302726922", "html": "I have homework due tomorrow, 3 questions only, but I don't know shit about them!<br />\nAnd here it's 10:35 pm!", "user": "ywkbme" }, { "id": "68667", "time": "1302731372", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/marymansour/\">marymansour</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">If this is just a derivative, when f(x)=(x+3)^2, f'(x) = 2(x+3). Easy :)</div></div><br />\n<br />\nErr, wouldn't it be (x+3)*(x+3), which would make the answer x^2+6x+9? The complications arise when h is introduced. But no matter. I've already turned it in.", "user": "burritofamine" }, { "id": "68677", "time": "1302732291", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/burritofamine/\">Burrito Famine</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">Err, wouldn't it be (x+3)*(x+3), which would make the answer x^2+6x+9? The complications arise when h is introduced. But no matter. I've already turned it in.</div></div><br />\n<br />\nNo, it wouldn't. The Power Rule easily proves when f(x) = (x+3)^2, f'(x) = 2(x+3).<br />\n<br />\nAs for when h is used, as above, f(x + h) is usually used as part of the formula "lim(h-->0) ( ( f(x+h) - f(x) ) / h )", which, if f(x) = (x+3)^2, will equal 2(x+3).<br />\n<br />\n<img src=\"/uploads/files/172114.jpg\" alt=\"172114.jpg\" />", "user": "wildface" }, { "id": "68684", "time": "1302732922", "html": "Ok, thank you very much. I'm going in for tutorials tomorrow. I obviously don't understand it at all.", "user": "burritofamine" }, { "id": "68812", "time": "1302744427", "html": "<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/ywkbme/\">ywkbme</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">I have homework due tomorrow, 3 questions only, but I don't know shit about them!<br />\nAnd here it's 10:35 pm!</div></div><br />\nLet us help. O_o", "user": "beary605" }, { "id": "69014", "time": "1302758701", "html": "I'm fine, a friend helped me! :D", "user": "ywkbme" }, { "id": "69030", "time": "1302760087", "html": "My math teacher says that if you've got a geometry problem, and you can't make sense of it, draw random lines that pass through at least one point (preferably 2). You'll eventually get a line that'll make you click.<br />\n<div style=\"margin:20px; background-image:url(/images/light.png);\"><div style=\"border:1px solid #888; padding:5px;\"><a href=\"/users/sporeinsanity/\">SporeInsanity</a> said:</div><div style=\"border:1px solid #888; padding:20px;\">Not really a problem but just a question.<br />\n<br />\nExplain how Sine^-1 turns sine into an angle, usually theta :P</div></div><br />\nWell, if sin(theta) gives the sine of an angle, then Sin^-1(theta) should do the inverse... right?", "user": "beary605" }, { "id": "75337", "time": "1303677038", "html": "<a href=\"/uploads/files/Untitled54_1.png\">Simple math problem that I just can't figure out.</a>", "user": "eitakxner" } ], "users": { "beary605": { "name": "beary605", "key": "beary605", "url": "/users/beary605", "avatar": "/images/white.png", "rankClass": "civilian", "rankText": "", "posts": "1090" }, "sporeinsanity": { "name": "Spore Insanity", "key": "sporeinsanity", "url": "/users/sporeinsanity", "avatar": "/uploads/drawn/592.png", "rankClass": "civilian", "rankText": "", "posts": "3670" }, "sophrosyne": { "name": "Sophrosyne", "key": "sophrosyne", "url": "/users/sophrosyne", "avatar": "/uploads/drawn/3473.png", "rankClass": "comrade", "rankText": "АДМИНИСТРАТОР", "posts": "3499" }, "burritofamine": { "name": "Burrito Famine", "key": "burritofamine", "url": "/users/burritofamine", "avatar": "/images/white.png", "rankClass": "civilian", "rankText": "", "posts": "645" }, "hydrogen777": { "name": "Hydrogen777", "key": "hydrogen777", "url": "/users/hydrogen777", "avatar": "/uploads/drawn/11933.png", "rankClass": "admin", "rankText": "Admin", "posts": "7571" }, "fwip": { "name": "Fwip", "key": "fwip", "url": "/users/fwip", "avatar": "/uploads/drawn/583.png", "rankClass": "admin", "rankText": "Admin", "posts": "3744" }, "marymansour": { "name": "marymansour", "key": "marymansour", "url": "/users/marymansour", "avatar": "/images/white.png", "rankClass": "civilian", "rankText": "", "posts": "1" }, "ywkbme": { "name": "ywkbme", "key": "ywkbme", "url": "/users/ywkbme", "avatar": "/images/white.png", "rankClass": "civilian", "rankText": "", "posts": "8321" }, "verum": { "name": "Verum", "key": "verum", "url": "/users/verum", "avatar": "/uploads/drawn/1365.png", "rankClass": "civilian", "rankText": "", "posts": "3597" }, "wildface": { "name": "Wildface", "key": "wildface", "url": "/users/wildface", "avatar": "/uploads/drawn/164.png", "rankClass": "civilian", "rankText": "", "posts": "20052" }, "eitakxner": { "name": "Eitakxner", "key": "eitakxner", "url": "/users/eitakxner", "avatar": "/images/white.png", "rankClass": "civilian", "rankText": "", "posts": "196" } }, "page_num": 1, "locked": 0, "total_pages": 53 }

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