表达式2: left parenthesis, "u" , "f" left parenthesis, "u" , right parenthesis cos "v" , "f" left parenthesis, "u" , right parenthesis sin "v" , right parenthesisu,fucosv,fusinv
定义域u最小值： 00
less than or equal to "u" less than or equal to≤u≤
定义域u最大值： 55
00
定义域v最小值：
less than or equal to "v" less than or equal to≤v≤
