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[Stack-cvs] stack-1-0/lang/en/doc student_input.php,1.3,1.4
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From: Chris S. <san...@us...> - 2005-08-26 08:45:06
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Update of /cvsroot/stack/stack-1-0/lang/en/doc In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv10292/lang/en/doc Modified Files: student_input.php Log Message: Index: student_input.php =================================================================== RCS file: /cvsroot/stack/stack-1-0/lang/en/doc/student_input.php,v retrieving revision 1.3 retrieving revision 1.4 diff -C2 -d -r1.3 -r1.4 *** student_input.php 25 Aug 2005 16:06:17 -0000 1.3 --- student_input.php 26 Aug 2005 08:44:56 -0000 1.4 *************** *** 1,480 **** <?php - /** - * - * STACK: A system for teaching and assessment using a - * computer algebra kernel. - * <br> - * This file is licensed under the GPL License. - * <br> - * A copy of the license is in your STACK distribution called - * license.txt. If you are missing this file you can obtain - * it from: - * http://www.stack.bham.ac.uk/license.txt - * <br> - * Copyright (c) 2005, Christopher James Sangwin - * - * @author Chris Sangwin C.J...@bh... - * - * @package documentation ! ! * @subpackage Stack ! */ - - - - ?> - - <a name="entry"><h2>How do I enter my answers?</h2></a> - ! ! You should type in your answers using the same syntax used in the ! ! symbolic mathematics package, known as a computer algebra system ! ! (cas), underpinning your implementation. This could be ! ! either <i>Axiom</i> or <i>Maxima</i>. The syntax is broadly similar ! ! to the syntax used for mathematical formulae in general programming ! ! languages such as Java, C and Basic and in spreadsheet programs such ! ! as Excel, so you will find it useful to master it. If you are ! ! taking the Applied Mathematics Core course AMA101 then you will ! ! learn to use such a system there. If you are not, the advice below should ! ! be sufficient. Stack tries quite hard to give helpful information ! ! about syntax errors. You can also learn about the right syntax by ! ! doing tests in practice mode and asking for ! ! the solutions; as well as displaying the right answers in ordinary ! ! mathematical notation, Stack will tell you how they could be ! ! entered. (However, there are often several possible ways, and Stack ! ! will not always suggest the easiest one.) ! ! <br /><br /> ! ! When you have entered your answer, you can always click on the ! ! <b>Validate</b> button at the bottom of the page to see how the CAS will ! ! interpret it. If there are any syntax errors or the cas has ! ! misunderstood what you meant then you can fix the problem before ! ! asking Stack to mark your work. ! ! <ul> ! ! <li> Numbers like <font color="BLUE">1/4</font> should be entered as ! <tt><font color="GREEN">1/4</font></tt>, not as ! ! <tt><font color="GREEN">0.25</font></tt>, which can cause some ! ! subtle problems. ! </li> ! ! <li> Use a star for multiplication: for example, ! ! <font color="BLUE">3x</font> should be ! ! entered as <tt><font color="GREEN">3*x</font></tt>. Forgetting this ! ! is by far the most ! ! common source of syntax errors. Note that you do <b>not</b> need ! ! a semicolon at the end, unlike when you are using a CAS directly. ! ! <br /><br /></li> ! ! <li> Use a caret (^) for raising something to a power: for example, ! <font color="BLUE">x<sup>2</sup></font> should be entered as - <tt><font color="GREEN">x^2</font></tt>. You can get - a caret by holding down the SHIFT key and pressing the 6 key - on most keyboards. Negative or fractional powers need brackets: ! ! enter <font color="BLUE">x<sup>-2</sup></font> as ! ! <tt><font color="GREEN">x^(-2)</font></tt> ! ! and <font color="BLUE">x<sup>1/3</sup></font> as ! ! <tt><font color="GREEN">x^(1/3)</font></tt>. ! ! <br /><br /></li> ! ! <li> More generally, when in doubt, use brackets. For example, ! <font color="BLUE"> - <center><table border="0" align="center"><tbody><tr><td> - <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> - </td><td nowrap="nowrap" align="center"> - a + b<hr noshade="noshade"> - c + d <br /></td><td nowrap="nowrap" align="center"> - </td></tr></tbody></table> - </td></tr></tbody></table></center> - </font> - should be entered as - <tt><font color="GREEN">(a+b)/(c+d)</font></tt>. - Note that in this context you should always use ordinary round - bracket (like <tt><font color="GREEN">(a+b)</font></tt>), not - square or curly ones (like <tt><font color="GREEN">[a+b]</font></tt> - or <tt><font color="GREEN">{a+b}</font></tt>). - <br /> - If you type ! ! <tt><font color="GREEN">a+b/(c+d)</font></tt>, then Stack ! will think that you mean - <font color="BLUE"> - <center><table border="0" align="center"><tbody><tr><td> - <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> - a +</td><td nowrap="nowrap" align="center"> - b<hr noshade="noshade"> - c + d<br /></td><td nowrap="nowrap" align="center"> - </td></tr></tbody></table> - </td></tr></tbody></table></center> - </font> ! ! If you type <tt><font color="GREEN">(a+b)/c+d</font></tt>, then Stack ! will think that you mean - <font color="BLUE"> - <center><table border="0" align="center"><tbody><tr><td> - <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> - </td><td nowrap="nowrap" align="center"> - a + b<hr noshade="noshade"> - c<br /></td><td nowrap="nowrap" align="center"> - + d </td></tr></tbody></table> - </td></tr></tbody></table></center> - </font> ! ! If you type <tt><font color="GREEN">a+b/c+d</font></tt>, then Stack ! will think that you mean - <font color="BLUE"> - <center><table border="0" align="center"><tbody><tr><td> - <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> - a +</td><td nowrap="nowrap" align="center"> - b<hr noshade="noshade"> - c<br /></td><td nowrap="nowrap" align="center"> - + d </td></tr></tbody></table> - </td></tr></tbody></table></center> - </font> - <br /> - Some other examples: - <ul> - <li> - <font color="BLUE">2<sup>a+b</sup></font> should be entered as - <tt><font color="GREEN">2^(a+b)</font></tt> - </li> - <li> - <font color="BLUE">2 cos 3x</font> should be entered as - <tt><font color="GREEN">2*cos(3*x)</font></tt> - </li> - <li> - <font color="BLUE">e<sup>ax</sup>sin(bx)</font> should be entered as - <tt><font color="GREEN">exp(a*x)*sin(b*x)</font></tt> - </li> - <li> - <font color="BLUE">(a x<sup>2</sup> + b x + c)<sup>-1</sup></font> - should be entered as - <tt><font color="GREEN">(a*x^2 + b*x + c)^(-1)</font></tt>. - </li> - </ul> ! ! <br /><br /></li> ! ! <li>the CAS system is case-sensitive. Do not enter ! ! <tt><font color="GREEN">X</font></tt> instead of ! ! <tt><font color="GREEN">x</font></tt>, or ! ! <tt><font color="GREEN">a</font></tt> instead of ! ! <tt><font color="GREEN">A</font></tt>, or ! ! <tt><font color="GREEN">Log(Z)</font></tt> instead of ! ! <tt><font color="GREEN">log(z)</font></tt>. ! ! </li> ! ! <li>The absolute value of <font color="BLUE">x</font>, which is ! ! written as <font color="BLUE">|x|</font> in traditional notation, ! ! must be entered as <tt><font color="GREEN">abs(x)</font></tt>. ! ! </li> ! ! <li> ! ! Standard functions such as sin, cos, tan, exp, log and so on can ! be entered using their usual names. However, the argument must - <font color="RED">always</font> be enclosed in brackets: - <font color="BLUE">sin x</font> should be entered as - <tt><font color="GREEN">sin(x)</font></tt>, - <font color="BLUE">ln 3</font> should be entered as ! <tt><font color="GREEN">ln(3)</font></tt> and so on. You can use either <tt><font color="GREEN">log(x)</font></tt> or - <tt><font color="GREEN">ln(x)</font></tt> for - the natural logarithm of x (note that both of these start with a ! lower case l, not a capital I). The function ! ! <font color="BLUE">1/sin(x)</font> must be ! ! referred to as <tt><font color="GREEN">csc(x)</font></tt> rather ! ! than <tt><font color="GREEN">cosec(x)</font></tt> (or you can just call ! ! it <tt><font color="GREEN">1/sin(x)</font></tt> if you prefer). You ! ! should always write ! ! <tt><font color="GREEN">exp(x)</font></tt> for ! ! <font color="BLUE">e<sup>x</sup></font>. ! ! <br /><br /></li> ! ! <li> ! ! <font color="BLUE">sin<sup>2</sup>x</font> should be entered as ! ! <tt><font color="GREEN">sin(x)^2</font></tt> (which is ! ! what it really means, after all). Similarly for ! ! <font color="BLUE">tan<sup>2</sup>(x)</font>, ! ! <font color="BLUE">sinh<sup>2</sup>(x)</font> and so on. ! ! <br /><br /></li> ! ! <li> ! ! Recall that <font color="BLUE">sin<sup>-1</sup>(x)</font> ! ! traditionally means the number <font color="BLUE">t</font> such that ! ! <font color="BLUE">sin(t) = x</font>, which is of ! ! course completely different from the number ! ! <font color="BLUE">sin(x)<sup>-1</sup> = 1/sin(x)</font>. This ! ! traditional notation is really rather unfortunate and is not used ! ! by the CAS; instead, <font color="BLUE">sin<sup>-1</sup>(x)</font> ! ! should be entered as <tt><font color="GREEN">arcsin(x)</font></tt>. ! ! Similarly, <font color="BLUE">tan<sup>-1</sup>(x)</font> should be ! ! entered as <tt><font color="GREEN">arctan(x)</font></tt> and so on. ! ! <br /><br /></li> ! ! <li> ! ! Greek letters can be entered using their English names: for ! example, enter - <font face="SYMBOL" color="BLUE">a+b</font> - as <tt><font color="GREEN">alpha+beta</font></tt>, and - <font face="SYMBOL" color="BLUE">2p</font> - as <tt><font color="GREEN">2*pi</font></tt>. ! ! <br /><br /></li> ! ! <li> ! ! When you work directly with a CAS, the vector <font color="BLUE">(1,2,3)</font> must be entered as ! ! <tt><font color="GREEN">vector([1,2,3])</font></tt>. Many Stack ! ! questions are set up so that you can just enter <tt><font color="green">[1,2,3]</font></tt> instead. ! </li> ! ! <li> ! ! When you work directly with a CAS, the matrix ! <font color="BLUE"> - </font><center><table border="0" align="center"><tbody><tr><td> - <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> - </td><td align="left"><font face="symbol"> - é<br />ê<br /> - ë - </font></td><td align="center"> - </td><td nowrap="nowrap"><table border="0" align="left"><tbody><tr><td nowrap="nowrap" align="center"> - <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> - 1 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> - <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> - 2 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> - <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> - 3 </td></tr></tbody></table></td></tr><tr><td nowrap="nowrap" align="center" colspan="1"><table border="0"><tbody><tr><td nowrap="nowrap" align="center"> - 4 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> - <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> - 5 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> - <table><tbody><tr><td nowrap="nowrap" align="center" colspan="1">6</td></tr></tbody></table></td></tr></tbody></table> - </td><td nowrap="nowrap"></td><td align="left"><font face="symbol"> - ù<br />ú<br /> - û - </font></td><td align="center"> - </td></tr></tbody></table> - </td></tr></tbody></table></center> - - must be entered as - <tt><font color="GREEN">matrix([1,2,3],[4,5,6])</font></tt>. </li> ! </ul> --- 1,331 ---- <?php /** * * STACK: A system for teaching and assessment using a * computer algebra kernel. * <br> * This file is licensed under the GPL License. * <br> * A copy of the license is in your STACK distribution called * license.txt. If you are missing this file you can obtain * it from: * http://www.stack.bham.ac.uk/license.txt * <br> * Copyright (c) 2005, Christopher James Sangwin * * @author Chris Sangwin C.J...@bh... * * @package documentation ! * @subpackage STACK */ ?> <a name="entry"><h2>How do I enter my answers?</h2></a> ! <p>In STACK you often need to enter an answer which is an ! <em>algebraic expression</em>. You should type in your ! answers using the same syntax as that used in the ! symbolic mathematics package <i>Maxima</i>. The syntax is broadly similar ! to the syntax used for mathematical formulae in graphical calculators, general programming ! languages such as Java, C and Basic and in spreadsheet programs, ! so you will find it useful to master it.</p> ! ! <p>STACK tries quite hard to give helpful information about any syntax errors. ! It might also forgive some errors you make. <ul> ! <li> <b>Numbers:</b> You should type in numbers without spaces, and use fractions rather ! than decimals where possible. For example, <font color="BLUE">1/4</font> should be entered as <tt><font color="GREEN">1/4</font></tt>, not as ! <tt><font color="GREEN">0.25</font></tt>. ! Also, ! <ul> ! <li> <font color="BLUE" face="symbol">p</font> is entered as either <tt><font color="GREEN">pi</font></tt> or <tt><font color="GREEN">%pi</font></tt>, </li> ! <li> <font color="BLUE">e</font>, the base of the natural logarithms, is entered as either <tt><font color="GREEN">e</font></tt> or <tt><font color="GREEN">%e</font></tt>, </li> ! <li> <font color="BLUE" face="symbol">Ö</font><font color="BLUE">-1</font> ! is entered as either <tt><font color="GREEN">i</font></tt> or <tt><font color="GREEN">%i</font></tt>, </li> ! <li> <font color="BLUE" face="symbol">Ö</font><font color="BLUE">-1</font> is also sometimes entered as <tt><font color="GREEN">j</font></tt> if you are an engineer. If in doubt ask your teacher. ! You could also use <tt><font color="GREEN">sqrt(-1)</font></tt>, or <tt><font color="GREEN">(-1)^(1/2)</font></tt>, being careful with the brackets.</tt> ! </li> ! </ul> ! (STACK modifies Maxima's normal input rules so that you don't get caught out with a variable <tt><font color="GREEN">i</font></tt> when you meant <tt><font color="GREEN">%i</font></tt>.) ! <br /><br /> </li> ! <li> <b>Multiplication:</b> Use a star for multiplication. Forgetting this ! is by far the most common source of syntax errors. For example, ! <ul> ! <li><font color="BLUE">3x</font> should be entered as <tt><font color="GREEN">3*x</font></tt>.</li> ! <li><font color="BLUE">x(ax+1)(x-1)</font> should be entered as <tt><font color="GREEN">x*(a*x+1)*(x-1)</font></tt>.</li> ! </ul> ! <br /><br /> ! </li> ! <li> <b>Powers:</b> Use a caret (^) for raising something to a power: for example, <font color="BLUE">x<sup>2</sup></font> should be entered as <tt><font color="GREEN">x^2</font></tt>. You can get a caret by holding down the SHIFT key and pressing the 6 key on most keyboards. Negative or fractional powers need brackets: ! <ul> ! <li><font color="BLUE">x<sup>-2</sup></font> should be entered as <tt><font color="GREEN">x^(-2)</font></tt>.</li> ! <li><font color="BLUE">x<sup>1/3</sup></font> should be entered as <tt><font color="GREEN">x^(1/3)</font></tt>.</li> ! </ul> ! <br /><br /> ! </li> ! <li> <b>Brackets:</b> Brackets are important to group terms in an expression. This is ! particularly the case in STACK since we use a <em>one dimensional input</em> rather than ! traditional written mathematics. When in doubt, use brackets, and also the <a href="#validate">validate</a> ! button to display your input in two dimensional form. For example, <font color="BLUE"> <center><table border="0" align="center"><tbody><tr><td> <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> </td><td nowrap="nowrap" align="center"> a + b<hr noshade="noshade"> c + d <br /></td><td nowrap="nowrap" align="center"> </td></tr></tbody></table> </td></tr></tbody></table></center> </font> should be entered as <tt><font color="GREEN">(a+b)/(c+d)</font></tt>. Note that in this context you should always use ordinary round bracket (like <tt><font color="GREEN">(a+b)</font></tt>), not square or curly ones (like <tt><font color="GREEN">[a+b]</font></tt> or <tt><font color="GREEN">{a+b}</font></tt>). <br /> If you type ! <tt><font color="GREEN">a+b/(c+d)</font></tt>, then STACK will think that you mean <font color="BLUE"> <center><table border="0" align="center"><tbody><tr><td> <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> a +</td><td nowrap="nowrap" align="center"> b<hr noshade="noshade"> c + d<br /></td><td nowrap="nowrap" align="center"> </td></tr></tbody></table> </td></tr></tbody></table></center> </font> ! If you type <tt><font color="GREEN">(a+b)/c+d</font></tt>, then STACK will think that you mean <font color="BLUE"> <center><table border="0" align="center"><tbody><tr><td> <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> </td><td nowrap="nowrap" align="center"> a + b<hr noshade="noshade"> c<br /></td><td nowrap="nowrap" align="center"> + d </td></tr></tbody></table> </td></tr></tbody></table></center> </font> ! If you type <tt><font color="GREEN">a+b/c+d</font></tt>, then STACK will think that you mean <font color="BLUE"> <center><table border="0" align="center"><tbody><tr><td> <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> a +</td><td nowrap="nowrap" align="center"> b<hr noshade="noshade"> c<br /></td><td nowrap="nowrap" align="center"> + d </td></tr></tbody></table> </td></tr></tbody></table></center> </font> <br /> Some other examples: <ul> <li> <font color="BLUE">2<sup>a+b</sup></font> should be entered as <tt><font color="GREEN">2^(a+b)</font></tt> </li> <li> <font color="BLUE">2 cos 3x</font> should be entered as <tt><font color="GREEN">2*cos(3*x)</font></tt> </li> <li> <font color="BLUE">e<sup>ax</sup>sin(bx)</font> should be entered as <tt><font color="GREEN">exp(a*x)*sin(b*x)</font></tt> </li> <li> <font color="BLUE">(a x<sup>2</sup> + b x + c)<sup>-1</sup></font> should be entered as <tt><font color="GREEN">(a*x^2 + b*x + c)^(-1)</font></tt>. </li> </ul> ! <br /><br /> ! </li> ! <li><b>Standard functions:</b> Functions, such as sin, cos, tan, exp, log and so on can be entered using their usual names. However, the argument must <font color="RED">always</font> be enclosed in brackets: <font color="BLUE">sin x</font> should be entered as <tt><font color="GREEN">sin(x)</font></tt>, <font color="BLUE">ln 3</font> should be entered as + <tt><font color="GREEN">ln(3)</font></tt> and so on. + <br /><br /> + </li> ! <li><b>Exponential function:</b> ! You should always write <tt><font color="GREEN">exp(x)</font></tt> for ! <font color="BLUE">e<sup>x</sup></font>. (Typing <tt><font color="GREEN">e^x</font></tt> ! should work in STACK, but gets you into bad habits when using a CAS later!) ! <br /><br /> ! </li> + <li><b>Logarithm:</b> You can use either <tt><font color="GREEN">log(x)</font></tt> or <tt><font color="GREEN">ln(x)</font></tt> for the natural logarithm of x (note that both of these start with a + lower case l, not a capital I). + <br /><br /> + </li> + + <li><b>Trigonometrical functions:</b> STACK uses radians for the angles <em>not</em> degrees! + <br />There are a number of important things to remember: + <ul> + <li> The function <font color="BLUE">1/sin(x)</font> must be + referred to as <tt><font color="GREEN">csc(x)</font></tt> rather + than <tt><font color="GREEN">cosec(x)</font></tt> (or you can just call + it <tt><font color="GREEN">1/sin(x)</font></tt> if you prefer).</li> + <li> + <font color="BLUE">sin<sup>2</sup>x</font> should be entered as + <tt><font color="GREEN">sin(x)^2</font></tt> (which is + what it really means, after all). Similarly for + <font color="BLUE">tan<sup>2</sup>(x)</font>, + <font color="BLUE">sinh<sup>2</sup>(x)</font> and so on. + </li> + <li> + Recall that <font color="BLUE">sin<sup>-1</sup>(x)</font> + traditionally means the number <font color="BLUE">t</font> such that + <font color="BLUE">sin(t) = x</font>, which is of + course completely different from the number + <font color="BLUE">sin(x)<sup>-1</sup> = 1/sin(x)</font>. This + traditional notation is really rather unfortunate and is not used + by the CAS; instead, <font color="BLUE">sin<sup>-1</sup>(x)</font> + should be entered as <tt><font color="GREEN">asin(x)</font></tt>. + Similarly, <font color="BLUE">tan<sup>-1</sup>(x)</font> should be + entered as <tt><font color="GREEN">atan(x)</font></tt> and so on. + </li> + </ul> + <br /><br /> + </li> + <li><b>Modulus function:</b> The modulus function, sometimes called the absolute value of <font color="BLUE">x</font>, is + written as <font color="BLUE">|x|</font> in traditional notation. + This must be entered as <tt><font color="GREEN">abs(x)</font></tt>. + </li> ! <li><b>Greek letters</b> can be entered using their English names. For example, enter <font face="SYMBOL" color="BLUE">a+b</font> as <tt><font color="GREEN">alpha+beta</font></tt>, and <font face="SYMBOL" color="BLUE">2p</font> as <tt><font color="GREEN">2*pi</font></tt>. ! <br /><br /> </li> ! ! <li><b>Sets:</b> To enter a set such as <font color="BLUE">{1,2,3}</font> ! in Maxima you are expected to use the function <tt><font color="GREEN">set(1,2,3)</font></tt>. ! STACK also allows you to use curly brackets and type <tt><font color="GREEN">{1,2,3}</font></tt>. ! <br /><br /> ! </li> ! ! <li><b>Lists:</b> can be entered using square brackets. ! For example, to enter the list <font color="BLUE">1,2,2,3</font> ! type <tt><font color="GREEN">[1,2,2,3]</font></tt>. ! <br /><br /> ! </li> ! ! <li><b>Matrices:</b> You may be given a grid of boxes to fill in. If not, the teacher may ! provide a hint as to the correct syntax. Otherwise you will need to use Maxima's notation ! for entering the matrix. <br /><br /> ! The matrix <font color="BLUE"> </font><center><table border="0" align="center"><tbody><tr><td> <table align="left"><tbody><tr><td nowrap="nowrap" align="center"> </td><td align="left"><font face="symbol"> é<br />ê<br /> ë </font></td><td align="center"> </td><td nowrap="nowrap"><table border="0" align="left"><tbody><tr><td nowrap="nowrap" align="center"> <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> 1 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> 2 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> 3 </td></tr></tbody></table></td></tr><tr><td nowrap="nowrap" align="center" colspan="1"><table border="0"><tbody><tr><td nowrap="nowrap" align="center"> 4 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> <table border="0"><tbody><tr><td nowrap="nowrap" align="center"> 5 </td></tr></tbody></table></td><td nowrap="nowrap" align="center"> <table><tbody><tr><td nowrap="nowrap" align="center" colspan="1">6</td></tr></tbody></table></td></tr></tbody></table> </td><td nowrap="nowrap"></td><td align="left"><font face="symbol"> ù<br />ú<br /> û </font></td><td align="center"> </td></tr></tbody></table> </td></tr></tbody></table></center> must be entered as <tt><font color="GREEN">matrix([1,2,3],[4,5,6])</font></tt>. + <p>Each <em>row</em> is entered as a list, and these should be the same length. The + function <font color="GREEN">matrix</font></tt> is used to indicate this is a matrix + and not a "list of lists".</p> </li> ! <!-- <li>the CAS system is case-sensitive. Do not enter ! <tt><font color="GREEN">X</font></tt> instead of ! <tt><font color="GREEN">x</font></tt>, or ! <tt><font color="GREEN">a</font></tt> instead of ! <tt><font color="GREEN">A</font></tt>, or ! <tt><font color="GREEN">Log(Z)</font></tt> instead of ! <tt><font color="GREEN">log(z)</font></tt>. ! </li> --> </ul> + + + <p>Note that you do <b>not</b> need + a semicolon at the end, unlike when you are using a CAS directly.</p> + + You can also learn about the right syntax by + doing tests in practice mode and asking for + the solutions; as well as displaying the right answers in ordinary + mathematical notation, STACK will tell you how they could be + entered. (However, there are often several possible ways, and STACK + will not always suggest the easiest one.)</p> + + <a name="quiz"><h2>What do the various links do?</h2></a> + + <a name="validate"><h3>Validate</h3></a> + + <p>When you have entered your answer, you can always click on the + <b>Validate</b> link to see how STACK will interpret it. Your answer will + be checked for syntax errors and, assuming there are none, will be displayed + in a traditional two dimensional from. If there are any syntax errors or the CAS has + misunderstood what you meant then you can fix the problem before + asking STACK to mark your work. There are no marks and no cumulative penalties for + using validate, and you are advised strongly to validate before you mark. + </p> + + <p>Validate also stores your answers in the database. If you would like to return + to a quiz later, but do not want to mark your work yet, press validate to record your current answers. + You will be able to change them and mark your work later, up to any "due date" for a quiz + of course. At some point you must login and decide to mark your work, however. + If you are taking a long time to answer all the questions in a quiz then it is a good + idea to press validate every time you enter a new answer to safeguard against + a problem with a connection to the internet.</p> + + <h3>Mark or Mark this question</h3> + + <p>Pressing this link asks STACK to assess your answer, provide feedback and record a mark. + You will almost always be given more than one attempt, but this may alter the marks.</p> + + <h3>Focus</h3> + <p>This enables you to concentrate on just one question at a time.</p> + + <h3>Unfocus</h3> + + <p>This enables you to see all the questions on one page, which is useful when you start a + quiz or wish to print the page.</p> + + <h3>Solutions</h3> + + <p>Sometimes solutions will be available. If you opt to see the solutions you will not be then + able to change your answers!</p> + + <h3>New version</h3> + + <p>Sometimes you will be able to generate another similar quiz.</p> + |
