表达式12: "s" left parenthesis, "t" , right parenthesis equals left parenthesis, cos left parenthesis, negative 2 times 2 "t" pi , right parenthesis times 2 plus cos left parenthesis, 2 pi "t" , right parenthesis times 6 plus cos left parenthesis, negative 2 times 2 "t" pi , right parenthesis times 3 , sin left parenthesis, negative 2 times 2 "t" pi , right parenthesis times 2 plus sin left parenthesis, 2 pi "t" , right parenthesis times 6 plus sin left parenthesis, negative 2 times 2 pi "t" , right parenthesis times 3 , right parenthesisst=cos−2·2tπ·2+cos2πt·6+cos−2·2tπ·3,sin−2·2tπ·2+sin2πt·6+sin−2·2πt·3
12
表达式13: "d" left parenthesis, "t" , right parenthesis equals left parenthesis, cos left parenthesis, 2 pi "t" , right parenthesis times 6 plus cos left parenthesis, negative 2 times 2 "t" pi , right parenthesis times 3 , sin left parenthesis, 2 pi "t" , right parenthesis times 6 plus sin left parenthesis, negative 2 times 2 pi "t" , right parenthesis times 3 , right parenthesisdt=cos2πt·6+cos−2·2tπ·3,sin2πt·6+sin−2·2πt·3
13
表达式14: left brace, "t" greater than 1 half : "d" left parenthesis, 1 minus mod left parenthesis, 2 "t" , 1 , right parenthesis , right parenthesis , "s" left parenthesis, mod left parenthesis, 2 "t" , 1 , right parenthesis , right parenthesis , right bracet>12:d1−mod2t,1,smod2t,1
00
定义域t最小值：
less than or equal to "t" less than or equal to≤t≤
定义域t最大值： "c" minus 10 to the negative 4th powerc−10−4
