Paul's Online Notes
Paul's Online Notes
Home / Algebra / Preliminaries / Radicals
Show Mobile Notice Show All Notes Hide All Notes
Mobile Notice
You appear to be on a device with a "narrow" screen width (i.e. you are probably on a mobile phone). Due to the nature of the mathematics on this site it is best viewed in landscape mode. If your device is not in landscape mode many of the equations will run off the side of your device (you should be able to scroll/swipe to see them) and some of the menu items will be cut off due to the narrow screen width.

Section 1.3 : Radicals

12. Simplify the following expression. Assume that \(x\), \(y\) and \(z\) are positive.

\[\sqrt[4]{{4{x^3}y}}\,\,\sqrt[4]{{8{x^2}{y^3}{z^5}}}\]

Show All Steps Hide All Steps

Start Solution

Remember that when we have a product of two radicals with the same index in an expression we first need to combine them into one root before we start the simplification process.

\[\sqrt[4]{{4{x^3}y}}\,\,\sqrt[4]{{8{x^2}{y^3}{z^5}}} = \,\sqrt[4]{{\left( {4{x^3}y} \right)\left( {8{x^2}{y^3}{z^5}} \right)}} = \,\sqrt[4]{{32{x^5}{y^4}{z^5}}}\] Show Step 2

Now that the expression has been written as a single radical we can proceed as we did in the earlier problems.

The radicand can be written as,

\[32{x^5}{y^4}{z^5} = \left( {{2^4}{x^4}{y^4}{z^4}} \right)\left( {2xz} \right)\] Show Step 3

Now that we’ve gotten the radicand rewritten it’s easy to deal with the radical and get the expression in simplified radical form.

\[\sqrt[4]{{4{x^3}y}}\,\,\sqrt[4]{{8{x^2}{y^3}{z^5}}} = \,\sqrt[4]{{32{x^5}{y^4}{z^5}}} = \sqrt[4]{{{2^4}{x^4}{y^4}{z^4}}}\,\,\sqrt[4]{{2xz}} = \require{bbox} \bbox[2pt,border:1px solid black]{{2xyz\,\,\sqrt[4]{{2xz}}}}\]