question_answer 1)

Find the inverse of matrix .  

Answer:

Let                   is non-singular matrix so A?1 exists.             A11 = (?1)1+1(?cos2 ?sin2 ) = ?1;       A12 = (?1)1+2(0 ? 0) = 0;       A13 = (?1)1+3(0 ? 0) = 0;       A21 = (?1)2+1(0 ? 0) = 0;       A22 = (?1)2+2(?cos  ? 0) = ? cos ;       A23 = (?1)2+3(sin  ? 0) = ?sin ;       A31 = (?1)3+1(0 ? 0) = 0;       A32 = (?1)3+2(? sin  ? 0) = ? sin ;       A33 = (?1)3+3(cos  ?0) = cos ;             Now