To Collect Terms

Symbolics > Working with Symbolics > Simplifying and Rewriting Expressions > To Collect Terms

To Collect Terms

1. Type a polynomial expression of two variables, such as x and y.

2. Place the cursor at the end of the expression and insert the symbolic evaluation operator.

3. Type the keyword collect in the placeholder.

Alternatively, on the Math tab, in the Operators and Symbols group, click Symbolics and select collect from the Keywords list.

4. Type a comma after collect and specify variable x.

<region id="ID0ENG6LB" actualWidth="528.98" actualHeight="39.2" top="38.400000000000006" left="19.200000000000003" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="4">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <plus />
        <apply>
          <plus />
          <apply>
            <plus />
            <apply>
              <mult />
              <apply>
                <mult />
                <real>3</real>
                <apply>
                  <pow />
                  <id xml:space="preserve">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <id xml:space="preserve">y</id>
            </apply>
            <apply>
              <mult />
              <apply>
                <mult />
                <real>5</real>
                <apply>
                  <pow />
                  <id xml:space="preserve">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <apply>
                <pow />
                <id xml:space="preserve">y</id>
                <real>2</real>
              </apply>
            </apply>
          </apply>
          <apply>
            <mult />
            <apply>
              <mult />
              <real>7</real>
              <id xml:space="preserve">x</id>
            </apply>
            <apply>
              <pow />
              <id xml:space="preserve">y</id>
              <real>2</real>
            </apply>
          </apply>
        </apply>
        <apply>
          <mult />
          <id xml:space="preserve">x</id>
          <id xml:space="preserve">y</id>
        </apply>
      </apply>
      <command>
        <sequence>
          <id xml:space="preserve">collect</id>
          <id xml:space="preserve">x</id>
        </sequence>
      </command>
      <symResult>
        <apply>
          <plus />
          <apply>
            <mult />
            <id xml:space="preserve" labels="*">x</id>
            <parens>
              <apply>
                <plus />
                <apply>
                  <mult />
                  <real>7</real>
                  <apply>
                    <pow />
                    <id xml:space="preserve" labels="*">y</id>
                    <real>2</real>
                  </apply>
                </apply>
                <id xml:space="preserve" labels="*">y</id>
              </apply>
            </parens>
          </apply>
          <apply>
            <mult />
            <apply>
              <pow />
              <id xml:space="preserve" labels="*">x</id>
              <real>2</real>
            </apply>
            <parens>
              <apply>
                <plus />
                <apply>
                  <mult />
                  <real>5</real>
                  <apply>
                    <pow />
                    <id xml:space="preserve" labels="*">y</id>
                    <real>2</real>
                  </apply>
                </apply>
                <apply>
                  <mult />
                  <real>3</real>
                  <id xml:space="preserve" labels="*">y</id>
                </apply>
              </apply>
            </parens>
          </apply>
        </apply>
      </symResult>
    </symEval>
  </math>
</region>

PTC Mathcad collects terms in polynomials containing like powers of the variable that you specify.

5. Change the variable to y and view the changed result.

<region id="ID0ERI6LB" actualWidth="529.17" actualHeight="39.2" top="115.20000000000002" left="19.200000000000003" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="5">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <plus />
        <apply>
          <plus />
          <apply>
            <plus />
            <apply>
              <mult />
              <apply>
                <mult />
                <real>3</real>
                <apply>
                  <pow />
                  <id xml:space="preserve">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <id xml:space="preserve">y</id>
            </apply>
            <apply>
              <mult />
              <apply>
                <mult />
                <real>5</real>
                <apply>
                  <pow />
                  <id xml:space="preserve">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <apply>
                <pow />
                <id xml:space="preserve">y</id>
                <real>2</real>
              </apply>
            </apply>
          </apply>
          <apply>
            <mult />
            <apply>
              <mult />
              <real>7</real>
              <id xml:space="preserve">x</id>
            </apply>
            <apply>
              <pow />
              <id xml:space="preserve">y</id>
              <real>2</real>
            </apply>
          </apply>
        </apply>
        <apply>
          <mult />
          <id xml:space="preserve">x</id>
          <id xml:space="preserve">y</id>
        </apply>
      </apply>
      <command>
        <sequence>
          <id xml:space="preserve">collect</id>
          <id xml:space="preserve">y</id>
        </sequence>
      </command>
      <symResult>
        <apply>
          <plus />
          <apply>
            <mult />
            <parens>
              <apply>
                <plus />
                <apply>
                  <mult />
                  <real>5</real>
                  <apply>
                    <pow />
                    <id xml:space="preserve" labels="*">x</id>
                    <real>2</real>
                  </apply>
                </apply>
                <apply>
                  <mult />
                  <real>7</real>
                  <id xml:space="preserve" labels="*">x</id>
                </apply>
              </apply>
            </parens>
            <apply>
              <pow />
              <id xml:space="preserve" labels="*">y</id>
              <real>2</real>
            </apply>
          </apply>
          <apply>
            <mult />
            <parens>
              <apply>
                <plus />
                <apply>
                  <mult />
                  <real>3</real>
                  <apply>
                    <pow />
                    <id xml:space="preserve" labels="*">x</id>
                    <real>2</real>
                  </apply>
                </apply>
                <id xml:space="preserve" labels="*">x</id>
              </apply>
            </parens>
            <id xml:space="preserve" labels="*">y</id>
          </apply>
        </apply>
      </symResult>
    </symEval>
    <resultFormat>
      <matrix size="12,12" offset="0,0" show-indices="false" expand-nested-arrays="false" />
    </resultFormat>
  </math>
</region>

6. Verify that if the expression contains a single variable, then the variable name can be omitted.

<region id="ID0ECK6LB" actualWidth="325.83666666666664" actualHeight="39.2" top="172.8" left="19.200000000000003" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math resultRef="6">
    <symEval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <mult />
        <apply>
          <pow />
          <id xml:space="preserve">x</id>
          <real>2</real>
        </apply>
        <parens>
          <apply>
            <plus />
            <apply>
              <plus />
              <apply>
                <scale />
                <real>5</real>
                <apply>
                  <pow />
                  <id xml:space="preserve">x</id>
                  <real>2</real>
                </apply>
              </apply>
              <apply>
                <scale />
                <real>10</real>
                <id xml:space="preserve">x</id>
              </apply>
            </apply>
            <real>1</real>
          </apply>
        </parens>
      </apply>
      <command>
        <id xml:space="preserve">collect</id>
      </command>
      <symResult>
        <apply>
          <plus />
          <apply>
            <plus />
            <apply>
              <mult />
              <real>5</real>
              <apply>
                <pow />
                <id xml:space="preserve" labels="*">x</id>
                <real>4</real>
              </apply>
            </apply>
            <apply>
              <mult />
              <real>10</real>
              <apply>
                <pow />
                <id xml:space="preserve" labels="*">x</id>
                <real>3</real>
              </apply>
            </apply>
          </apply>
          <apply>
            <pow />
            <id xml:space="preserve" labels="*">x</id>
            <real>2</real>
          </apply>
        </apply>
      </symResult>
    </symEval>
  </math>
</region>