If f^-1(y) is the inverse of f(x) which statements must be true?

a) f(f^-1(x))=x
b) f^-1(f(x))=x
c) the range of f^-1(y) is the range of f(x)
d) the range of f^-1(y) is the domain of f(x)
e) the domain of f^-1(y) is the range of f(x)
f) the domain of f^-1(y) is the domain of f(x)

Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. these cyclotrons typically accelerate h- (the hydride ion, which has one proton and two electrons) to an energy of 5 mev to 20 mev. this ion has a mass very close to that of a proton because the electron mass is negligible—about 1 2000 of the proton’s mass. a typical magnetic field in such cyclotrons is 1.9 t. (a) what is the speed of a 5.0-mev h-? (b) if the h- has energy 5.0 mev and b = 1.9 t, what is the radius of this ion’s circular orbit?