Expression 4: "y" equals left brace, 0 less than or equal to "x" less than or equal to StartFraction, 2 pi Over "b" , EndFraction : "a" , right bracey=0≤x≤2πb:a
4
Expression 5: "x" equals left brace, 0 greater than or equal to "y" greater than or equal to negative "a" : StartFraction, pi Over "b" , EndFraction , right bracex=0≥y≥−a:πb