Simplifying Radical Expressions on TI-84 Plus

Question

Hi,

 

Wondering if anyone can help me simplify radical expressions on my TI-84 Plus.  Some questions like finding the squre root of 36 I have no problem with but when I try to enter something like the 5th root of 32/243 I can't get it to work it says 1.8144... and the correct answer is 2/3.  I am entering 5 radical sign, (32/243) .  THANKS in advance for any help!

 

Linda

Answer 1

You want to essentially do them separately...find the 5th root of 32 first.  When you factor 32, you get 2 * 2 * 2 * 2 * 2.  We have a group of five 2's with nothing left over.  Therefore 5th root of 32 is 2.  Write the 2 in the numerator.  Next find the 5th root of 243.  When you factor 243, you get 3 * 3 * 3 * 3 * 3.  We have a group of five 3's with nothing left over.  Therefor the 5th root of 243 is 3.  Write the 3 in the denominator.  You now have your answer 2/3.  You can also enter (32/243)^(1/5) which give you .66666667 then press the "MATH" button and select the first option which is the "to Frac" option.  Press enter again and it will convert that decimal into the fraction 2/3.

 

Good luck.

Justin

Answer 2

I have the TI-84 Plus and got the answer of 2/3:

try 5 Math 5 (2/243) enter then change decimal to fraction.