# Daniel I. Scully

## A Beginner's Guide to MathML

### Roots

For displaying a square-root MathML provides the <msqrt> tag:

1. <msqrt>
2.  <mi>x</mi><mo>+</mo><mn>2</mn>
3. </msqrt>
$\sqrt{x+2}$

For more general roots there is the <mroot> tag. Unlike the <msqrt>, which can contain any number of child tags, the <mroot> must contain exactly two. Again the order is important: the first element is the expression being rooted, and the second is the power of the root.

Below is an example of a cubic root in which, to satisfy the two child rule , the expression being acted upon is grouped within an <mrow> tag:

1. <mroot>
2.  <mrow>
3.  <mi>x</mi><mo>+</mo><mn>2</mn>
4.  </mrow>
5.  <mn>3</mn>
6. </mroot>
$\sqrt[3]{x+2}$