Defines the line segment from (0,0) to (a,b), then rotated by R
8
นิพจน์ 9: left parenthesis, left parenthesis, "a" times "a" Subscript, 11 , Baseline left parenthesis, "c" , right parenthesis plus "b" times "a" Subscript, 12 , Baseline left parenthesis, "c" , right parenthesis , right parenthesis "t" , left parenthesis, "a" times "a" Subscript, 21 , Baseline left parenthesis, "c" , right parenthesis plus "b" times "a" Subscript, 22 , Baseline left parenthesis, "c" , right parenthesis , right parenthesis "t" , right parenthesisa·a11c+b·a12ct,a·a21c+b·a22ct
