The inverse of the function y=[1−(x−3)4]1/7 is

Clearly y is one-one and onto. We have, y=[1−(x−3)4]1/7 ⇒      (x−3)4=1−y7 ⇒       x=3+(1−y7)1/4 ⇒       f−1(y)=3+(1−y7)1/4