Let f(x)=x2 and g(x) =sin x for all x∈R. Then the set of all x satisfying (fogogof) (x) =(gogof) (x), where (fog) (x) =f(g(x)), is
(fogogof)(x)=sin2(sinx2)(gogof)(x)=sin(sinx2)∴sin2(sinx2)=sin(sinx2)⇒sin(sinx2)[sin(sinx2)−1]=0⇒sin(sinx2)=0or1
⇒sinx2=nπor2mπ+π2, where m,n∈I
⇒sinx2=0⇒x2=nπ⇒x=±√nπ,n∈{0,1,2,....}