Ekspresi 4: left parenthesis, "x" minus StartFraction, pi Over 2 , EndFraction , right parenthesis squared plus left parenthesis, "z" , right parenthesis squared minus left parenthesis, "y" , right parenthesis squared equals "t" left brace, negative 2cos left parenthesis, "k" minus pi , right parenthesis less than "y" less than 2cos left parenthesis, "k" minus pi , right parenthesis , right bracex−π22+z2−y2=t−2cosk−π<y<2cosk−π
4
Ekspresi 5: left parenthesis, "x" minus StartFraction, 3 pi Over 4 , EndFraction , right parenthesis squared plus left parenthesis, "y" , right parenthesis squared minus left parenthesis, "z" , right parenthesis squared equals "t" left brace, negative 2sin left parenthesis, "k" minus pi , right parenthesis less than "z" less than 2sin left parenthesis, "k" minus pi , right parenthesis , right brace left brace, "k" greater than 3.3 , right bracex−3π42+y2−z2=t−2sink−π<z<2sink−πk>3.3
