User Comments - RJ
RJ
Posted on: Learning about Levels
November 27, 2011 at 1:16 PMLWT
at bottom center of the dashboard is a button labeled "all lessons". Click this and it will take you to the manage lessons page. Until recently this button was labeled "manage lessons" but that made too much sense so they changed it. :-) Actually the site is not that tough to navigate once you play with it for a while. Oh, and to change your level, there is a very small grey "cogwheel" button upper right corner of the dashboard. Click here to change settings such as level.
Posted on: Essential Math Terms
November 27, 2011 at 12:49 PMBodawei,
yes, guilty as charged, but it sounds as bad to me as it does to you. Interesting how ingrained arbitrary things can become. I suggest we call a truce on this one and agree to use the word mathematics to spare both our ears. As you have noted elsewhere I have tried to sneak in a change to the spelling of trigonometry in retaliation but you have caught me red handed, or should I say fat fingered, seeing how this was actually a typo. Hey maybe thats how maths came about? Sorry, last jab, I promise. My favorite maths villain advocate to antagonize was GoManly. I kind of miss picking on Bob. Anyway I thought you would enjoy the Roo mnemonic associated with the Chinese word for algebra as commented on elsewhere, I myself will never forget 代数 vs 袋鼠 and you have to love Chinese for describing a kangaroo as a bag rat, albeit a rather large one.
Posted on: Essential Math Terms
November 26, 2011 at 11:04 PMactually its not wrong. f'(x²) =2x. At the point x=3 it is 6. The equation does change for f'(x²) but I wasnt able to type the whole thing over (its difficult to type such forms in this environment). hence the .... but it would follow the same basic definition of a derivative and you would replace 3 with an x in all places and solving would yield 2x . This is the basic definition. Nobody uses that once the process is learned. There are derived equations - in this case f'(x^n) = n(x^n-1). I have no way to delete anything at this point. Delete it all for all I care - it matters not. It all started with a joke anyway. Im sure you have instructed your students properly so they will not be confused by my notation or shortcuts. Sorry I brought it up.
Posted on: Essential Math Terms
November 26, 2011 at 8:05 PMAh, I see but you left out the statement:
"Here is a particular example, the derivative of the squaring function at the input 3. Let f(x) = x² be the squaring function"
that would have made it clear. Usually you solve for the fucntion x² and the answer would be 2x. So at any point the slope = 2X, so at x=3 the answer is 6. They just solved it knowing the function was x²,at the point x=3. Your paste didnt provide that information. and that is what markt was saying as well, but I thought he was just backing it out of the situation. In wikipedia it is a "Given" condition to the problem.
bottom line- we are all right.
now, hey gregE how about some help translating :-)
Posted on: Essential Math Terms
November 26, 2011 at 6:52 PMthen the equation should read f'(x²) = ..... instead of f'(3) =.....
in this case the solution to the equation would be 2x and yes at x=3 the answer would be 6 but this isnt a math class. I only wish I could translate the entire expression in Chinese.
Posted on: Essential Math Terms
November 26, 2011 at 5:22 PMThanks Bill, interesting, young guy too.
Posted on: Essential Math Terms
November 26, 2011 at 4:53 PM哈哈 I would tell you but the equation is wrong. The derivative of 3 is zero (not 6) . In fact the derivative of any constant is zero. Your numerator should not have any squared terms in it.
Posted on: Essential Math Terms
November 26, 2011 at 4:04 PMtry
http://hua.umf.maine.edu/Chinese/games/numbers/chinese/one.html
Posted on: Essential Math Terms
November 26, 2011 at 11:31 AMsome additional tidbits:
微积分 wēijīfēn - calculus
导数 - dǎoshù - Derivative
积分 - jīfēn - Integral
矢量 - shīliàng - Vector
张量 - zhāngliàng - Tensor
三角法 -sānjiǎofǎ - Triginometry
正弦 -zhèngxián - Sine
余弦 - yúxián - Cosine
正切 - zhèngqiē - Tangent
正割 - zhènggē - Secant
几何 - jǐhé - Geometry
代数 - dàishù - algebra (not to be confused with 袋鼠 dàishǔ (kangaroo)
微分方程 - wēifēnfāngchéng - Differential Equations
Posted on: Essential Math Terms
November 27, 2011 at 1:33 PMNo disrespect intended. I like Roos. Frozen tail? Oh thats right, its a delicacy according to the Aborigines I think. That would make a great "who-dunnit" for baba. Cant buy Roo meat here yet. At least I havent seen it. So how about you? Any Kanga bangas in your freezer?