Author a formula that matches responses to within +C sub-type
This sub-type is authored by selecting the Formula that matches responses to within +C option from the Sub-type drop-down list during mathematical formula question authoring.
Examples of accepted syntax for defining the Answer field value for this sub-type are:
x*ln(x)x*ln(x) +1(4/3)*x^3 + (7/5)*x^5 + (11/7)*x^7
The formula that matches responses to within +C sub-type Answer field:
Accepts numbers and formulas.
Accepts many valid answers that differ by the addition of a constant number.
Accepts equivalent responses by treating two answers as equivalent if they differ by a constant number.
Example of this sub-type
Question statement:
Evaluate
∫ 4x2 + 7x4 + 11x6dx
Answer field syntax:
(4/3)*x^3 + (7/5)*x^5 + (11/7)*x^7
Example of this sub-type with an algorithm
Question statement:
Evaluate
∫ $a*x^$r + $b*x^$s + $c*x^$t dx
Algorithm:
$r=rint(2, 10);
$s=rint(2, 10);
$t=rint(2, 10);
condition: gt($r,$s) gt($s,$t);
$rplus=int($r+1);
$splus=int($s+1);
$tplus=int($t+1);
$a=rint(2,20);
$b=rint(2,20);
$c=rint(2,20);
Answer field syntax:
($a/$rplus)*x^$rplus + ($b/$splus)*x^$splus + ($c/$tplus)*x^$tplus