表达式3: "g" left parenthesis, "x" , right parenthesis equals left brace, negative "c" less than or equal to "x" less than or equal to "c" : StartFraction, 1 Over StartRoot, 2 "c" , EndRoot , EndFraction , "x" less than negative "c" : 0 , "x" greater than "c" : 0 , right bracegx=−c≤x≤c:12c,x<−c:0,x>c:0
3
表达式4: "G" left parenthesis, "t" , right parenthesis equals StartFraction, sin left parenthesis, "c" "t" , right parenthesis Over StartRoot, pi "c" , EndRoot "t" , EndFractionGt=sinctπct
