Expression 3: left parenthesis, "x" squared plus "y" squared , right parenthesis equals left parenthesis, 1 minus StartFraction, "S" Over 10 , EndFraction "z" , right parenthesis squared left brace, "z" equals StartFraction, "x" Over 2 , EndFraction , right bracex2+y2=1−S10z2z=x2