# CBSE Important Questions class XII mathematics 2008 4

Q. 1. If sin y = xcos(a + y) and find k (3 marks)

Q. 2. If f(x) = find f’(o) (3marks)

Q. 3. Verify the mean value theorem for f(x) = in [1,3] (4 marks)

Q. 4. If x = a ( + ) y = (1 + cos ) find (4 marks)

Q. 5. If xpyq = (x + y) p+q prove that

Or

(4 marks)

Q. 6. Consider the function defined as follows for . In each case ,what choice (if any) of f(0) will make the function continuous at x = 0.

(4 marks)

Q. 7. If x = acos + bsin y = asin - bcos(4 marks)

Q. 8.

Or

(4 marks)

1. Construct a3 x 3 matrix A = [aij]whose elements are given by aij = ( 3 marks)
2. Solve the matrix equation for x (3 marks)
3. Solve the following equation for x (3 marks)
4. Prove that = a + b + c (3 marks)
5. Solve the following equations for using matrices x - y + z = 4 2x + y -3z = 0 x + y + z = 2 ( 6 marks)
6. Determinant of a skew symmetrix matrix of odd orderis always ( 1 marks)
a) zero
b) one
c) negative one
d) none
7. If A is a square matrix of order 3 then A.Adj (A) is (1 marks)

a) | A | I3
b) | A | I2
C) | A | I
d) none

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