y=[sin(x^4)]^2dy/dx=2[sin(x^4)]. d/dx {sin(x^4)}=2[sin(x^4)]. cos(x^4) . d/dx (x^4)=2[sin(x^4)]. cos(x^4) . (4x^3)=8x^3.sin(x^4). cos(x^4)
