運算式 3: "P" equals left parenthesis, cos left parenthesis, alpha , right parenthesis , sin left parenthesis, alpha , right parenthesis , 0 , right parenthesisP=cosα,sinα,0
運算式 4: "P" plus left parenthesis, negative "P" . "y" , "P" . "x" , left bracket, 1 , negative 1 , right bracket , right parenthesis "t"P+−P.y,P.x,1,−1t
定義域 t 最小值： negative 4−4
less than or equal to "t" less than or equal to≤t≤
