Expression 4: StartRoot, left parenthesis, "x" minus StartRoot, 3 , EndRoot cos left parenthesis, 2 pi "s" , right parenthesis , right parenthesis squared plus left parenthesis, "y" minus StartRoot, 3 , EndRoot sin left parenthesis, 2 pi "s" , right parenthesis , right parenthesis squared , EndRoot plus StartRoot, left parenthesis, "x" plus StartRoot, 3 , EndRoot cos left parenthesis, 2 pi "s" , right parenthesis , right parenthesis squared plus left parenthesis, "y" plus StartRoot, 3 , EndRoot sin left parenthesis, 2 pi "s" , right parenthesis , right parenthesis squared , EndRoot equals 4x−3cos2πs2+y−3sin2πs2+x+3cos2πs2+y+3sin2πs2=4