表达式7: "D" equals StartRoot, left parenthesis, left parenthesis, 0 , right parenthesis minus left parenthesis, 4sin "a" plus 2sin "a" , right parenthesis , right parenthesis squared plus left parenthesis, left parenthesis, 0 , right parenthesis minus left parenthesis, 2cos "a" plus cos "a" , right parenthesis , right parenthesis squared , EndRootD=0−4sina+2sina2+0−2cosa+cosa2
equals=
3.0 1 9 2 7 1 1 3 6 8 13.01927113681
7
表达式8: left parenthesis, "t" left parenthesis, 4cos "a" plus 1 half cos 5 "a" , right parenthesis , "t" left parenthesis, 5sin "a" plus sin 5 "a" , right parenthesis , right parenthesist4cosa+12cos5a,t5sina+sin5a
定义域t最小值： 00
less than or equal to "t" less than or equal to≤t≤
