Expression 3: StartRoot, left parenthesis, StartFraction, "d" Over "d" "x" , EndFraction StartFraction, "d" Over "d" "x" , EndFraction left parenthesis, "x" positive StartFraction, cos left parenthesis, "n" "x" , right parenthesis Over "x" , EndFraction , right parenthesis , right parenthesis squared positive left parenthesis, StartFraction, "d" Over "d" "x" , EndFraction StartFraction, "d" Over "d" "x" , EndFraction left parenthesis, "x" positive StartFraction, sin left parenthesis, "n" "x" , right parenthesis Over "x" , EndFraction , right parenthesis , right parenthesis squared , EndRootddxddxx+cosnxx2+ddxddxx+sinnxx2