Square Roots, Cube Roots & Nth Roots on the TI-84 Evo

The TI-84 Evo has a dedicated square root function, and the MATH menu carries cube roots and any-index roots.

Enter a square root

  1. Press 2nd, then x². The square root is the blue label above the x² key. Pressing 2nd and then x² opens a radical on the entry line.
    TI-84 Evo keyboard with the x-squared key highlighted, showing the square root label above it
  2. Type the number inside the radical. This example uses 144.
  3. Press enter for the answer. The calculator returns 12.
    The TI-84 Evo showing the square root of 144 evaluated to 12

Cube roots and higher

For cube roots and other roots, open the MATH menu. The cube root is item 4, and the general any-index root is item 5.

The TI-84 Evo MATH menu showing the cube root command as item 4 and the nth root as item 5

Cube root: press math, then 4. Type the number and press enter. The cube root of 27 is 3.

The TI-84 Evo showing the cube root of 27 evaluated to 3

Any root: press math, then 5. The calculator opens a template with two boxes. Type the index (the small number in front of the radical) first, press the right arrow to move into the radical, then type the number. For the fourth root of 81, type 4, press right, type 81, and press enter to get 3.

The TI-84 Evo showing the fourth root of 81 evaluated to 3

Good to know

  • Non-perfect roots give a decimal. The square root of 50 returns 7.071067812, not a simplified radical like 5√2. If your class needs simplified form, the radical simplifier program handles that.
  • Everything you type stays inside the radical bar until you press the right arrow to step out. If your expression continues past the root (like √9 + 1), press the right arrow after the 9 before typing +1.