HateEvent Posted April 13, 2011 Report Share Posted April 13, 2011 Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 13, 2011 Report Share Posted April 13, 2011 Show working. Quote Link to comment Share on other sites More sharing options...
Hugh_Jazz Posted April 13, 2011 Report Share Posted April 13, 2011 3sin^2x?complete guess.y = (sin ^ 3......this is a function in a function. So you need to use the chain rule.....dy/dx = dy/du . du/dx You need to split them out into parts.....ie. let's call (sin "u", which gives you:y = u^3Differentiating this gives: dy/du = 3u^2u = sin xdu/dx = cos xmultiply.....dy/dx = 3u^2.cos xsubstitute "u = sin x" into the above, and rearrange:dy/dx = 3(cos (sin ^2 2 Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 13, 2011 Report Share Posted April 13, 2011 y = (sin ^ 3......this is a function in a function....I had to... Quote Link to comment Share on other sites More sharing options...
Oedo 808 Posted April 13, 2011 Report Share Posted April 13, 2011 It's taken me a while to work out but I reckon it's 2. Quote Link to comment Share on other sites More sharing options...
Le Stu Posted April 13, 2011 Author Report Share Posted April 13, 2011 y = (sin ^ 3......this is a function in a function. So you need to use the chain rule.....dy/dx = dy/du . du/dx You need to split them out into parts.....ie. let's call (sin "u", which gives you:y = u^3Differentiating this gives: dy/du = 3u^2u = sin xdu/dx = cos xmultiply.....dy/dx = 3u^2.cos xsubstitute "u = sin x" into the above, and rearrange:dy/dx = 3(cos (sin ^2hope they don't ask me calculus questions, probably not if they're gonna teach me it. Quote Link to comment Share on other sites More sharing options...
Jeanette Posted April 13, 2011 Report Share Posted April 13, 2011 This thread hurts my head! Quote Link to comment Share on other sites More sharing options...
Monster Zero Posted April 13, 2011 Report Share Posted April 13, 2011 This thread has generated more interest than most of the music biased threads ever do. Unless it's ripping shit out of young kids and stuff. Go Aberdeen Music Scene. Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 13, 2011 Report Share Posted April 13, 2011 Maths > Music.Bulling > MusicMaths =/= Bullying.amirite? Quote Link to comment Share on other sites More sharing options...
Guest idol_wild Posted April 13, 2011 Report Share Posted April 13, 2011 Maths > Music.Bulling > MusicMaths =/= Bullying.amirite?Not if 'bulling' involves bovine sexual liaisons. Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 13, 2011 Report Share Posted April 13, 2011 Sex with water buffalo? Quote Link to comment Share on other sites More sharing options...
soundian Posted April 13, 2011 Report Share Posted April 13, 2011 rather than decimal. like:48_2using the sign implies the term on the left is divided by the term on the right. It doesn't represent a fraction as the coefficient. Brackets are expanded before division, and, since there are no unknowns, 2(9+3) expands to a single figure, 24. A fraction is just the term on the top divided by the term on the bottom. Easier to write that as a/b (which is the term on the left divided by the term on the right) on a computer and is entirely equal to ab (which is the term on the left divided by the term on the right). The obelus () does not impart some mystic property which the virgule (/) doesn't. They are merely different representations of the same thing. The brackets seem to be confusing you, so lets remove them by resolving the term inside 482x12Now, since multiplication has the same precedence as division, which do you do first? Quote Link to comment Share on other sites More sharing options...
Hugh_Jazz Posted April 13, 2011 Report Share Posted April 13, 2011 obelusI like this word. I think I might use it for my next band. Virgule can be the first album. Quote Link to comment Share on other sites More sharing options...
soundian Posted April 13, 2011 Report Share Posted April 13, 2011 I like this word. I think I might use it for my next band. Virgule can be the first album. A virgule can also be called a solidus--first single? Obelus is pretty good for a band name, but there is no Joy in Division it seems. Quote Link to comment Share on other sites More sharing options...
Hugh_Jazz Posted April 13, 2011 Report Share Posted April 13, 2011 A virgule can also be called a solidus--first single?Excellent. All I need is a supergroup of maths geeks and we're away. Quote Link to comment Share on other sites More sharing options...
jon Posted April 13, 2011 Report Share Posted April 13, 2011 Quote Link to comment Share on other sites More sharing options...
Le Stu Posted April 13, 2011 Author Report Share Posted April 13, 2011 A fraction is just the term on the top divided by the term on the bottom. Easier to write that as a/b (which is the term on the left divided by the term on the right) on a computer and is entirely equal to ab (which is the term on the left divided by the term on the right). The obelus () does not impart some mystic property which the virgule (/) doesn't. They are merely different representations of the same thing. The brackets seem to be confusing you, so lets remove them by resolving the term inside 482x12Now, since multiplication has the same precedence as division, which do you do first?No confusion. It's a(b+c) resolving as ab+ac as multiplication of the juxtaposed coefficient must be distributed over the terms in parentheses to properly expand the brackets. you can't just make the coefficent the denominator of 48 as it's part of the expression 2(9+3) Quote Link to comment Share on other sites More sharing options...
soundian Posted April 14, 2011 Report Share Posted April 14, 2011 No confusion. It's a(b+c) resolving as ab+ac as multiplication of the juxtaposed coefficient must be distributed over the terms in parentheses to properly expand the brackets. you can't just make the coefficent the denominator of 48 as it's part of the expression 2(9+3) It's not necessarily part of the expression 2(9+3). You think it is because, in the interests of brevity, the multiplication sign is missed out. If you were to put that in a calculator you would have to include the multiplication sign because calculators are not programmed to understand the shorthand version. The calculator in windows gives the answer 288 btw. You can't enter it without the multiplication sign because the multiplication sign is there, whether you write it or not. The same issue arises with something simpler like 48/2x. I won't argue that whoever wrote it means that 48 should be divided by the product of 2 and x but mathematically it needs clarification if written on one line, say like on a calculator or in a line of software. As demonstrated by windows calculator, you may not get the answer you're looking for if you are sloppy with your input. Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 14, 2011 Report Share Posted April 14, 2011 A fraction is just the term on the top divided by the term on the bottom. Easier to write that as a/b (which is the term on the left divided by the term on the right) on a computer and is entirely equal to ab (which is the term on the left divided by the term on the right). The obelus () does not impart some mystic property which the virgule (/) doesn't. They are merely different representations of the same thing. The brackets seem to be confusing you, so lets remove them by resolving the term inside 482x12Now, since multiplication has the same precedence as division, which do you do first?You've got to get in to the habit of doing 2x9 and 2x3 then adding them together instead of 9+3 x2 because when shit gets heavy you have to multiply each individually first.Wait.. you're not doing engineering maths eh? Well you're doing it wrong anyway. Even though you get to the right destination the path you travelled was wrong.Hugh Jazz can I play bass? Quote Link to comment Share on other sites More sharing options...
soundian Posted April 14, 2011 Report Share Posted April 14, 2011 You've got to get in to the habit of doing 2x9 and 2x3 then adding them together instead of 9+3 x2 because when shit gets heavy you have to multiply each individually first.Wait.. you're not doing engineering maths eh? Well you're doing it wrong anyway. Even though you get to the right destination the path you travelled was wrong.Hugh Jazz can I play bass? From wikipedia:"... care must be exercised when using the slash ('/') symbol. The string of characters "1/2x" is interpreted by the above conventions as (1/2)x. The contrary interpretation should be written explicitly as 1/(2x). Again, the use of brackets will clarify the meaning and should be used if there is any chance of misinterpretation." Substituting our values above and making x=(9+3) 48/2x=(48/2)x=288 48/2(9+3)=(48/2)(9+3)=288 Has anybody got a bass amp I can borrow? Quote Link to comment Share on other sites More sharing options...
Scootray Posted April 14, 2011 Report Share Posted April 14, 2011 Fucking nerds. Quote Link to comment Share on other sites More sharing options...
Jaaakkkeee Posted April 15, 2011 Report Share Posted April 15, 2011 From wikipedia:"... care must be exercised when using the slash ('/') symbol. The string of characters "1/2x" is interpreted by the above conventions as (1/2)x. The contrary interpretation should be written explicitly as 1/(2x). Again, the use of brackets will clarify the meaning and should be used if there is any chance of misinterpretation." Substituting our values above and making x=(9+3) 48/2x=(48/2)x=288 48/2(9+3)=(48/2)(9+3)=288 Has anybody got a bass amp I can borrow?In the original question / wasn't used. I just can't be bothered using the other one. The answer's 2.I did this stuff for two and a half years. It's 2. Quote Link to comment Share on other sites More sharing options...
Teabags Posted April 15, 2011 Report Share Posted April 15, 2011 Excellent. All I need is a supergroup of maths geeks and we're away. Quote Link to comment Share on other sites More sharing options...
soundian Posted April 15, 2011 Report Share Posted April 15, 2011 In the original question / wasn't used. I just can't be bothered using the other one. The answer's 2.I did this stuff for two and a half years. It's 2. I did this stuff for 1 year in a physics degree (Engineering maths basically), then switched to maths degree, class prize in 2nd year etc etc etc. The answer is indeterminate because there are two possible answers. It is either 2 or 288 but you do not have enough information to decide which one the person meant. In any Uni maths exam that expression would result in marks off for being ambiguous. It needs more brackets! Quote Link to comment Share on other sites More sharing options...
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