lf f and g are one-one functions, then

(a)  fx=sinx  and gx=cox,  x∈0,π2Here, both f(x) and g(x) are one-one functions.But hx=fx+gx=sinx+cosx is many-one as h0=hπ/2=1(b)  hx=fxgx=sinxcosx=sin2x2is many-one, ash0=hπ/2=0.(c)   It is a fundamental property.