Expression 5: "x" squared plus "y" squared equals 1x2+y2=1
5
Expression 6: "x" squared plus "y" squared equals StartFraction, pi Over 8 , EndFraction plus 1 halfx2+y2=π8+12
6
Expression 7: "y" equals StartFraction, 2 Over pi , EndFraction "x" squared plus left parenthesis, cos left parenthesis, "x" , right parenthesis , right parenthesis squaredy=2πx2+cosx2