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.

NOTE: This question sub-type allows the student to choose whether they want to submit their response using Symbol Mode (using the Equation Editor) or Text Mode (as a single line using their keyboard).

NOTE: The formula that matches responses to within +C question is one of the ten sub-types of the mathematical formula question. Check out Choose a mathematical formula question sub-type for an explanation of each of the ten available mathematical formula question sub-types.

TIP: Check out Author a mathematical formula question for full question authoring instructions.

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:

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$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

NOTE: The dollar sign ($) character can only be used in mathematical formula questions when it's a part of a variable name. Be sure to define algorithmic variables in the Algorithm pane in order to use them in the Answer field.