運算式 2: "r" equals 0.1 5 left brace, , right bracer=0.15
定義域 \theta 最小值： 00
less than or equal to theta less than or equal to≤θ≤
定義域 \theta 最大值： 7878
equals=
0.1 50.15
2
`78°` left parenthesis, 0.2 5cos left parenthesis, 39 , right parenthesis , 0.2 5sin left parenthesis, 39 , right parenthesis , right parenthesis0.25cos39,0.25sin39
