The triangle fuzzy number (0.1,02.0.3) can be presented in a simplified, discrete form of pairs {(x, μ(x))} as {(0.1,0),(0.15,0.5),(0.2,1), 0.25,0.5),(0.3,0)}. To calculate the power 0.25 of this number replace values of x in the above notation by (x)0.25 and you will get the powered fuzzy number:
{(0.10 power,025,0),(0.15power0.25,0.5),(0.2,power0.25,1), (0.25,power0.25,0.5),(0.3,power0.25,0)}. To better understand this make a figure of the initial number and of the result.
According to the rules of fuzzy arithmetic, the following formula is used in the exponentiation:Ap =(mA(u))2/u. You have given a triangular number, that is, the type of the membership function is given, therefore, it is necessary to record the operation in the form of a functional dependency, in my opinion.
A0.25={(10u-1)0.25/u, (3-10u)0.25/u}
u=(0.1;0.3) is a continuous carrier of a fuzzy set !!!