+33615 0.25 is 1/4, so 81^0.25 is 81^(1/4) This means the fourth root of 81. That is, it is a number which, when raised to the power of 4 equals 81.
3^4 = 3*3*3*3 → 9*9 → 81
.
Are you not happy with Alan's answer? Why?
You take the square root of 81 =sqrt(81) = 9. Now, you take the square of 9 this time=sqrt(9) = 3.
In other words, when you see 81^0.25 =81^1/4, it means that you must take the square root of 81 twice, or the square root of a square root =81^1/2 =9^1/2 =3 because 3^2 x 3^2 =81.
