表达式4: left parenthesis, "t" times cos left parenthesis, "a" , right parenthesis , "t" times sin left parenthesis, "a" , right parenthesis , right parenthesist·cosa,t·sina
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： 1.51.5
4
表达式5: tangent left parenthesis, "x" , right parenthesistanx
5
标签 left parenthesis, "a" , tan left parenthesis, "a" , right parenthesis , right parenthesisa,tana
