There is a formula. Take the first title as an example. The lower third of the root number is equal to one third times the root number three. Similarly, the lower quarter of the root number is a quarter times the root number four, and the lower n is a third times the root number n ... I don't know if you understand.

1, one third times the root number three.

One-half radical fourteen

3, 1/y times xy under the radical sign.

4,2a times 2ab under the root sign.

See the figure for details: