most recent 30 from http://merspi.com.au 2010-07-30T10:53:45Z http://merspi.com.au/feeds/tag/maths http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://merspi.com.au/questions/2461/what-are-the-most-popular-graphic-calculators-used-in-the-maths-subjects Dave 2010-07-21T08:24:36Z 2010-07-21T08:53:37Z

<p>What are the most popular graphic calculators used in the maths subjects?</p> <p>TI89? etc</p>

http://merspi.com.au/questions/2290/converting-from-kj-mol-to-kj-g Menja Zovut Shnur 2010-07-02T12:52:26Z 2010-07-17T07:23:04Z

<p>If I divide the specific heat capacit in KJ/mol by the molar mass of the fuel in question, why do I get the specific heat capacity in KJ/g.</p> <p>KJx(g)/molxmol = KJg/mol^2 is not KJ/g according to my calculations.</p> <p>Could you please explain this? </p>

http://merspi.com.au/questions/2061/how-do-i-solve-this-quartic-equation olia 2010-06-02T11:11:44Z 2010-07-14T13:23:06Z

<ul> <li>I know 3 points: (0,0) (34,3) and (68,0)</li> <li>I also know the gradient at the origin (0,0) is -0.123,</li> <li>and the gradient at (68,) is 0.123</li> </ul> <p>If the general equation is y = ax⁴ + bx³ + cx² + dx + e</p> <p>How do I find a, b, and c? I know that d = -0.123 and e = 0.</p> <p>Please help! :(</p>

http://merspi.com.au/questions/2166/is-the-period-of-sin-4x-equal-to-pi-4-or-pi-2 rn 2010-06-09T00:16:21Z 2010-07-07T06:22:52Z

<p>Is the period of |sin 4x| equal to &pi;/4 or &pi;/2? </p> <p>Wouldn't it be &pi;/4, since we go '2&pi; over n'? The solution says it is &pi;/2 instead.</p>

http://merspi.com.au/questions/1827/how-do-i-solve-this-linear-approximation-question Impractical 2010-05-02T00:42:03Z 2010-07-06T00:22:51Z

<blockquote> <p>Show that f(x)=1/(2-x) can be approximated by f(x)=(1/2)+(x/4) for x close to 0.</p> </blockquote> <p>I am sure this is a linear approximation question, but I don't get it at all. Could I please have some help? Thanks so much.</p>

http://merspi.com.au/questions/1971/indicies-in-matrices Impractical 2010-05-23T06:53:34Z 2010-07-04T13:09:22Z

<p>How do we raise things to 'powers' and 'inverse powers' in matrix form or using matrix method?</p>

http://merspi.com.au/questions/1049/solving-two-equations-simultaneously James Spittal 2010-01-21T19:57:27Z 2010-07-03T08:30:51Z

<p>Hi all!</p> <p>Using simultaneous equations - how can we solve <em>y = x + 2</em> and <em>y = (2/(x+1)) - 1</em>?</p> <p>Thanks!</p>

http://merspi.com.au/questions/1764/how-does-the-change-of-base-log-formula-work Collin Li 2010-04-26T10:20:21Z 2010-07-03T07:44:26Z

<p>Can somebody please explain how this formula works?</p> <blockquote> <p>log_bx = log_ax / log_ab</p> </blockquote>

http://merspi.com.au/questions/2292/difficulty-of-different-years-vcaa-exams Menja Zovut Shnur 2010-07-02T15:14:55Z 2010-07-02T15:58:32Z

<p>Can you rank the past VCAA exams for the subjects that you studied in order of difficulty?</p>

http://merspi.com.au/questions/2245/cant-get-these-differentiate-sin-1-x-1-x1-and-2tan-1-rootx Dan 2010-06-20T05:31:42Z 2010-06-21T10:14:40Z

<p>I thought I mastered VCE differentiation, then these two questions turns up =P</p>

http://merspi.com.au/questions/2234/how-do-we-tell-if-equations-are-locus-of-a-circle Dan 2010-06-18T08:02:17Z 2010-06-18T12:24:20Z

<p><img src="http://img695.imageshack.us/img695/5413/19089603.jpg" alt="alt text"></p> <p>I understand how D is not a circle, but why are the other options circles?</p>

http://merspi.com.au/questions/2233/integrate-1-x2-x2 Dan 2010-06-18T05:46:03Z 2010-06-18T12:22:13Z

<p>Can't remember how to do these :(</p> <p>Integrate 1/(x^2 +x+2)</p>

http://merspi.com.au/questions/2165/how-do-i-change-this-into-a-single-fraction rn 2010-06-09T00:06:05Z 2010-06-09T05:32:54Z

<p>How do I put:</p> <p>2 sqrt(x² + 3) + x(2x+1)/sqrt(x² + 3) into a single fraction?</p>

http://merspi.com.au/questions/1942/if-cos-x-0-75-determine-the-value-of-sin3pi-2-x-cospi-x Dan 2010-05-20T07:54:47Z 2010-05-20T09:42:30Z

<p>Really stuck with this one, don't recall doing these in the text book</p>

http://merspi.com.au/questions/1938/how-do-we-determine-the-exact-value-of-4cos7pi-6-8sin5pi-4-and-tan7pi-3 Dan 2010-05-19T12:15:35Z 2010-05-19T12:47:32Z

<p>I know it's suppose to be basic, but I somehow forgot them =P</p> <p>4cos(7pi/6) 8sin(5pi/4) tan(7pi/3)</p>

http://merspi.com.au/questions/1616/what-does-it-mean-by-1-3e-7-on-the-calculator Dan 2010-04-11T07:32:18Z 2010-05-11T13:49:34Z

<p>I know it's suppose to be basic, but I was never taught it and it's really hard to google :P</p>

http://merspi.com.au/questions/1820/how-do-i-differentiate-an-inverse-trigonometric-function Impractical 2010-05-01T11:39:45Z 2010-05-11T13:31:56Z

<p>How do you differentiate an inverse trigonometric function (ie: tan inverse x)? Or, is there a way to get around having to do this?</p>

http://merspi.com.au/questions/1855/what-about-points-on-the-three-median-regression-separation-lines Cassie 2010-05-05T00:29:12Z 2010-05-05T00:29:12Z

<p>I have a question where two points end up on the line separating groups- middle and right. How do I use those point to work out the centre and right median points or do I leave them out?</p>

http://merspi.com.au/questions/1832/solve-this-linear-approximation-question Impractical 2010-05-02T09:17:28Z 2010-05-02T10:53:04Z

<blockquote> <p>Given that y = x⁴ - 5x³, find in terms of <em>a</em> the approximate increase in <em>y</em> as <em>x</em> increases from 2 to 2+a where a is small.</p> </blockquote> <p>Thank you!</p>

http://merspi.com.au/questions/1615/how-accurate-does-an-estimated-equation-need-to-be vee 2010-04-11T07:29:53Z 2010-04-11T07:53:53Z

<p><img src="http://i43.tinypic.com/vzeyyt.jpg" alt="Data plot over a 9-month period"></p> <p>How accurate does the equation have to be? I keep on getting a different answer to the back of the book.</p> <p>Thanks</p>

http://merspi.com.au/questions/1586/should-i-include-units-in-differentiation-problems Impractical 2010-04-07T04:28:11Z 2010-04-09T08:44:28Z

<p>Should we include (and will we be marked down if we don't) units like: m²/sec when answering questions on the <em>rate of change</em> in differentiation questions?</p> <p>And, I understand that when finding the anti-derivative of a gradient function, where the x axis is located is irrelevant (since there is unknown +C value). However, how do I determine how long each of the arms of the actual function should be? Are they proportional to the gradient function's "arms"?</p> <p><strong>For example:</strong> if there was a 2 cm gradient function straight line, and after the 2 cm it reaches the x-axis and it has its own gradient is negative. Then, would the quadratic of order 2 that forms have an "arm" that goes up to its maximum or minimum after 2 cm? </p>

http://merspi.com.au/questions/1588/solutions-error-in-differentiation-chapter-of-maths-quest-12 Impractical 2010-04-07T05:42:56Z 2010-04-07T06:17:19Z

<p>I believe there is an error in the Maths Quest 12 Differentiation Chapter 7 (Q7j)</p> <p>Shouldn't the answer be [4,∞) because of the 4 in bold?</p> <p><img src="http://www.freeimagehosting.net/uploads/cb9f36586f.jpg" alt="the 4 is in bold"></p> <p>Back of book solutions: (4,∞)</p>

http://merspi.com.au/questions/1578/when-can-i-use-the-union-in-set-notation-for-writing-domains Impractical 2010-04-06T02:09:40Z 2010-04-06T07:19:43Z

<p>I've seen domains in the following form: </p> <blockquote> <p>(-∞,-2) U (3,∞).</p> </blockquote> <p>So is it equally valid to use the following form as well?</p> <blockquote> <p>x &lt; -2 <strong>U</strong> x > 3</p> </blockquote>

http://merspi.com.au/questions/1575/how-is-this-dilated Tezza 2010-04-05T08:18:38Z 2010-04-05T09:02:31Z

<p>I had a question to ask how 2log_e(3x+6)-1 was transformed from log_e(x)</p> <p>I said:</p> <ul> <li>Dilated from the x axis by a factor of 2</li> <li><strong>Dilated from the y axis by a factor of 1/3</strong></li> <li>Translated 1 unit down</li> <li>Translated 2 units left</li> </ul> <p>However, the answers omit the "Dilated from the y axis by a factor of 1/3"</p> <p>Is this a misprint or am I wrong in this instance?</p>

http://merspi.com.au/questions/1572/data-sheet-contents Impractical 2010-04-05T07:08:40Z 2010-04-05T07:33:44Z

<p>In the yr 12 Math Methods Math Quest book, text questions on linear approximation are not given without the formula being initially given. This seems to suggest that the formula will be provided on examination data sheets. Can you confirm my suspicions? Similarly, equations such as 'volume of a cone' are provided in the book. Can I expect these sorts of formulas in the end of year examination?</p>

http://merspi.com.au/questions/1262/when-do-simultaneous-equations-with-three-variables-have-no-solution Hugh 2010-02-19T11:17:55Z 2010-03-30T07:22:57Z

<p>I think the determinant and matrices is required.</p>

http://merspi.com.au/questions/1467/need-help-with-3-fundamental-inverse-trig-questions Dan 2010-03-21T04:34:33Z 2010-03-21T08:17:30Z

<p>I was told these 3 questions were crucial to the understanding of the topic, but I can't manage to work them out</p> <ol> <li><p>(a) Find the exact value of sin^-1(sin 5&pi;/4)<br> (b) Why is the answer -&pi;/4 and not 5&pi;/4?</p></li> <li><p>(a) Find sin(sin^-1(-root2))<br> (b) Why is the answer undefined?</p></li> <li><p>(a) Find tan(2(sin^-1 5/13))</p></li> </ol>

http://merspi.com.au/questions/991/sketching-the-derivative-from-the-graphs-of-the-original-function Phresh 2010-01-19T12:34:01Z 2010-03-17T09:00:25Z

<p>Sketch the graphs of the derivative functions for each of the functions with the graphs shown.</p> <p><img src="http://i50.tinypic.com/1zb3oew.jpg" alt="Functions on a graph - find the derivative" /></p> <p>Do we have to find the equation of the above? And then differentiate it?</p> <p>Thanks</p>

http://merspi.com.au/questions/1408/how-do-you-move-1-3-for-the-three-median-regression-line Lex 2010-03-11T11:22:33Z 2010-03-13T02:25:36Z

<p>Is it only moved approximately 1/3 of the way up/down or do you need to solve to find the equation of the new line? </p> <p>Once the line has been moved, how do you figure out the equation of the line? Again do you pick two points on it by eye or is there another method? My textbook (Heinemann) seems to be saying that it relies on some judgement. Thanks.</p>

http://merspi.com.au/questions/1220/can-simultaneous-equations-have-an-infinite-number-of-solutions James Spittal 2010-02-15T22:54:20Z 2010-02-26T07:11:25Z

<p>Can simultaneous equations have an infinite number of solutions?</p>