1. Prove that the determinant sin cos sin 1 cos 1 x x x q q q q is independent of q. 2. Without expanding the determinant, prove that 2 2 3 2 2 3 2 2 3 1 1 1 = a a bc a a b b ca b b c c ab c c . 3. Evaluate cos cos cos sin sin sin cos 0 sin cos sin sin cos a b a b a b b a b a b a . 4. If a, b and c are real numbers, and D = b c c a a b c a a b b c a b b c c a + + + + + + + + + = 0, Show that either a + b + c = 0 or a = b = c. 5. Solve the equation 0 x a x x x x a x x x x a + + = + , a 0 6. Prove that 2 2 2 2 2 2 + + + a bc ac c a ab b ac ab b bc c = 4a2b2c2 7. If A1 = ( ) 1 3 1 1 1 2 2 15 6 5 and B 1 3 0 , find AB 5 2 2 0 2 1 = 8. Let A = 1 2 1 2 3 1 1 1 5 . Verify that (i) [adj A]1 = adj (A1) (ii) (A1)1 = A 9. Evaluate x y x y y x y x x y x y + + + 10.
Question 1:Prove that the determinant sin cos –sin – 1 cos 1 x x x q q q q is independent of q.
Question 2:Without expanding the determinant, prove that 2 2 3 2 2 3 2 2 3 1 1 1 = a a bc a a b b ca b b c c ab c c .
Question 3:Evaluate cos cos cos sin – sin – sin cos 0 sin cos sin sin cos a b a b a b b a b a b a .
Question 4:If a, b and c are real numbers, and D = b c c a a b c a a b b c a b b c c a + + + + + + + + + = 0, Show that either a + b + c = 0 or a = b = c.
Question 5:Solve the equation 0 x a x x x x a x x x x a + + = + , a ¹ 0
Question 6:Prove that 2 2 2 2 2 2 + + + a bc ac c a ab b ac ab b bc c = 4a2b2c2
Question 7:If A–1 = ( ) 1 3 1 1 1 2 2 15 6 5 and B 1 3 0 , find AB 5 2 2 0 2 1 – – – – – – – – =
Question 8:Let A = 1 2 1 2 3 1 1 1 5 é ë êêê ù û úúú . Verify that (i) [adj A]–1 = adj (A–1) (ii) (A–1)–1 = A
Question 9:Evaluate x y x y y x y x x y x y + + +
Question 10:Evaluate 1 1 1 x y x y y x x+ y + Using properties of determinants in Exercises 11 to 15, prove that:
Question 11:2 2 2 a a b + g b b g + a g g a + b = (b – g) (g – a) (a – b) (a + b + g)
Question 12:2 3 2 3 2 3 1 1 1 + + + x x px y y py z z pz = (1 + pxyz) (x – y) (y – z) (z – x), where π is any scalar.
Question 13:3 3 a 3c a – a+b – a+c –b a b – b c – c – c+b + + + = 3(a + b + c) (ab + bc + ca)
Question 14:1 1 1 2 3 2 4 3 2 3 6 3 10 6 3 π p q π p q π p q + + + + + + + + + = 1
Question 15:( ) ( ) ( ) sin cos cos sin cos cos 0 sin cos cos a a a + d b b b + d = g g g + d
Question 16:Solve the system of equations 2 3 10 + + = 4 x y z 4 6 5 – + =1 x y z 6 9 20 + – = 2 x y z Choose the correct answer in Exercise 17 to 19
Question 17:If a, b, c, are in A.P, then the determinant 2 3 2 3 4 2 4 5 2 x x x a x x x b x x x c + + + + + + + + + is (A) 0 (B) 1 (C) x (D) 2x
Question 18:If x, y, z are nonzero real numbers, then the inverse of matrix 0 0 A 0 0 0 0 x y z = is (A) 1 1 1 0 0 0 0 0 0 x y z − − − (B) 1 1 1 0 0 0 0 0 0 x xyz y z − − − (C) 0 0 1 0 0 0 0 x y xyz z (D) 1 0 0 1 0 1 0 0 0 1 xyz
Question 19:Let A = 1 sin 1 sin 1 sin 1 sin 1 q − q q − − q , where 0 ≤ q ≤ 2p. Then (A) Det (A) = 0 (B) Det (A) Î (2, ∞) (C) Det (A) Î (2, 4) (D) Det (A) Î [2, 4]