Expression 7: "G" left parenthesis, "x" , right parenthesis equals Start integral from 0 to "x" , end integral, "f" left parenthesis, "t" , right parenthesis "d" "t" left brace, 0 less than or equal to "x" less than or equal to "d" , right braceGx=∫x0ftdt0≤x≤d
7
Expression 8: "H" left parenthesis, "x" , right parenthesis equals "G" left parenthesis, "x" , right parenthesis plus "C"Hx=Gx+C