To Expand Expressions

Symbolics > Working with Symbolics > Factoring and Expanding Expressions > To Expand Expressions

1. Place the cursor at the end of the expression, insert the symbolic evaluation operator, and type the keyword expand in the placeholder. PTC Mathcad expands the expression by multiplying out powers and products.

<region id="ID0EIWNMB" actualWidth="306.56666666666666" actualHeight="39.2" top="38.400000000000006" left="0" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="3">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <pow />
        <parens>
          <apply>
            <plus />
            <id xml:space="preserve">x</id>
            <id xml:space="preserve">y</id>
          </apply>
        </parens>
        <real>3</real>
      </apply>
      <command>
        <id xml:space="preserve">expand</id>
      </command>
      <symResult>
        <apply>
          <plus />
          <apply>
            <plus />
            <apply>
              <plus />
              <apply>
                <pow />
                <id xml:space="preserve" labels="*">y</id>
                <real>3</real>
              </apply>
              <apply>
                <mult />
                <apply>
                  <mult />
                  <real>3</real>
                  <id xml:space="preserve" labels="*">x</id>
                </apply>
                <apply>
                  <pow />
                  <id xml:space="preserve" labels="*">y</id>
                  <real>2</real>
                </apply>
              </apply>
            </apply>
            <apply>
              <mult />
              <apply>
                <mult />
                <real>3</real>
                <apply>
                  <pow />
                  <id xml:space="preserve" labels="*">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <id xml:space="preserve" labels="*">y</id>
            </apply>
          </apply>
          <apply>
            <pow />
            <id xml:space="preserve" labels="*">x</id>
            <real>3</real>
          </apply>
        </apply>
      </symResult>
    </symEval>
  </math>
</region>

2. Type an algorithmic expression and use the expand keyword to expand it.

<region id="ID0E3XNMB" actualWidth="245.09666666666669" actualHeight="39.2" top="96.000000000000014" left="0" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="4">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <id xml:space="preserve" labels="FUNCTION" label-is-contextual="true">sin</id>
        <apply>
          <mult />
          <real>2</real>
          <id xml:space="preserve">x</id>
        </apply>
      </apply>
      <command>
        <id xml:space="preserve">expand</id>
      </command>
      <symResult>
        <apply>
          <mult />
          <apply>
            <mult />
            <real>2</real>
            <apply>
              <id xml:space="preserve" labels="FUNCTION">cos</id>
              <id xml:space="preserve" labels="*">x</id>
            </apply>
          </apply>
          <apply>
            <id xml:space="preserve" labels="FUNCTION">sin</id>
            <id xml:space="preserve" labels="*">x</id>
          </apply>
        </apply>
      </symResult>
    </symEval>
  </math>
</region>

3. To prevent a term in the expression from being expanded, type a comma-separated list of terms after expand. For example, to expand only the second binomial, add the first binomial as an argument.

<region id="ID0EQZNMB" actualWidth="355.15" actualHeight="39.2" top="153.60000000000002" left="0" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="5">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <mult />
        <parens>
          <apply>
            <plus />
            <id xml:space="preserve">x</id>
            <real>1</real>
          </apply>
        </parens>
        <parens>
          <apply>
            <plus />
            <id xml:space="preserve">y</id>
            <id xml:space="preserve">z</id>
          </apply>
        </parens>
      </apply>
      <command>
        <sequence>
          <id xml:space="preserve">expand</id>
          <parens>
            <apply>
              <plus />
              <id xml:space="preserve">x</id>
              <real>1</real>
            </apply>
          </parens>
        </sequence>
      </command>
      <symResult>
        <apply>
          <plus />
          <apply>
            <mult />
            <id xml:space="preserve" labels="*">z</id>
            <parens>
              <apply>
                <plus />
                <id xml:space="preserve" labels="*">x</id>
                <real>1</real>
              </apply>
            </parens>
          </apply>
          <apply>
            <mult />
            <id xml:space="preserve" labels="*">y</id>
            <parens>
              <apply>
                <plus />
                <id xml:space="preserve" labels="*">x</id>
                <real>1</real>
              </apply>
            </parens>
          </apply>
        </apply>
      </symResult>
    </symEval>
  </math>
</region>

• If the expression is a fraction, the numerator expands and the expression is written as a sum of fractions.

• Sines, cosines, and tangents of sums of variables, or integer multiples of variables, expand as far as possible into expressions involving only sines and cosines of single variables.

• If the expression cannot be expanded further, the expression remains unchanged.