Let f:R→[0,∞) be defined by f(x)=∣x−3∣. To make f invertible, its domain is restricted suitably. Which of the following choices gives a valid domain along with the correct expression for f−1(x)?
a) Domain [3,∞), f−1(x)=x−3
b) Domain [3,∞), f−1(x)=3+x
c) Domain (−∞,3], f−1(x)=x−3
d) Domain [3,∞), f−1(x)=∣x−3∣