## A Beginner's Guide to MathML

### Roots

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

`<msqrt>`

`<mi>x</mi><mo>+</mo><mn>2</mn>`

`</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:

`<mroot>`

`<mrow>`

`<mi>x</mi><mo>+</mo><mn>2</mn>`

`</mrow>`

`<mn>3</mn>`

`</mroot>`

$\sqrt[3]{x+2}$