Let R+ be the set of all non – negative real numbers. If f: R+ → R+ and g: R+ → R+ are defined as f(x) = x2 and g(x) = + √x. Find fog and gof. Are they equal functions.
We have, f : R+ → R+ given by
f (x) = x2
g: R + → R + given by
fog (x) = f(g(x)) = f(= (
)2 = x
Also,
gof (x) = g(f(x)) = g(x2) = = x
Thus,
fog(x)= gof (x)
They are equal functions as their domain and range are also equal.