---
metadata:
    display_name: Math Expression Input
    markdown: !!null
data: |
  <problem>
  <p>
  A math expression input problem accepts a line of text representing a mathematical expression from the
  student, and evaluates the input for equivalence to a mathematical expression provided by the 
  grader. Correctness is based on numerical sampling of the symbolic expressions.
  </p>
  <p>
  The answer is correct if both the student provided response and the grader's mathematical
  expression are equivalent to specified numerical tolerance, over a specified range of values for each
  variable.
  </p>

  <p>This kind of response checking can handle symbolic expressions, but places an extra burden
  on the problem author to specify the allowed variables in the expression, and the
  numerical ranges over which the variables must be sampled in order to test for correctness.</p>

  <script type="loncapa/python">
  VoVi = "(R_1*R_2)/R_3"
  </script>
  <p>Give an equation for the relativistic energy of an object with mass m.  Explicitly indicate multiplication with a <tt>*</tt> symbol.</p>
  <formularesponse type="cs" samples="m,c@1,2:3,4#10" answer="m*c^2">
      <responseparam type="tolerance" default="0.00001"/>
      <br/><text>E =</text> <formulaequationinput size="40" />
  </formularesponse>

  <p>The answer to this question is (R_1*R_2)/R_3. </p>

  <formularesponse type="ci" samples="R_1,R_2,R_3@1,2,3:3,4,5#10" answer="$VoVi">
      <responseparam type="tolerance" default="0.00001"/> 
      <formulaequationinput size="40" label="Enter the equation"/>    
  </formularesponse>
      <solution>
          <div class="detailed-solution">
              <p>Explanation</p>
              <p>The mathematical summary of many of the theory of relativity developed by Einstein is that the amount of energy contained in a mass m is the mass time the speed of light squared.</p>
              <p>As you can see with the formula entry, the answer is \(\frac{R_1*R_2}{R_3}\)</p>
          </div>
      </solution>
  </problem>
