Author an equation sub-type

This sub-type is authored by selecting the Equation 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 = 1 - 2y

  • y = 4*(x+1) +2

  • y = 8*(x-2) + 7

The equation sub-type Answer field:

  • Accepts the use of an "=" sign in the correct answer.

  • Accepts any equation that's algebraically equivalent to the correct answer as an equivalent response.

  • Requires the correct answer expression to have only a single variable on the left-hand side of the equation and a formula that doesn't involve that variable on the right-hand side (an implicit formula can't be specified).

Example of this sub-type

  • Question statement:

What is the equation of the straight line passing through the point (2, 7) with slope 8?

  • Answer field syntax:

y = 8*(x-2) + 7

Example of this sub-type with an algorithm

  • Question statement:

What is the equation of the straight line passing through the point ($xone, $yone) with a slope $m?

  • Algorithm:

$xone = rint(-10,10); $yone = decimal(1, rand(-10,10)); $m = rint(2, 10);

  • Answer field syntax:

y = $m*(x-$xone) + $yone