This is the test paper of Class-XI (J-Batch) .Take exactly 75 minutes. Q.1 If tan , tan are the roots of x2 – px + q = 0 and cot , cot are the roots of x2 – rx + s = 0 then find the value of rs in terms of p and q. [4] Q.2 Let P(x) = ax2 + bx + 8 is a quadratic polynomial. If the minimum value of P(x) is 6 when x = 2, find the values of a and b. [4] 1 Q.3 Let P = 102n1 then find log (P). [4] n1 sec 8A 1 0.01 tan 8A Q.4 Prove the identity sec 4A 1 = tan 2A . [4] Q.5 Find the general solution set of the equation logtan x(2 + 4 cos2x) = 2. [4] Q.6 Find the value of sin + sin 3 + sin 5 + + sin17 cos + cos 3 + cos 5 + + cos17 when = 24 . [4] Q.7(a) Sum the following series to infinity 1 1·4·7 1 + 4·7 ·10 1 + 7 ·10·13 + ........... (b) Sum the following series upto n-terms. 1 · 2 · 3 · 4 + 2 · 3 · 4 · 5 + 3 · 4 · 5 · 6 + ............. [3 + 3] Q.8 The equation cos2x – sin x + a = 0 has roots when x (0, /2) find 'a'. [6] Q.9 A, B and C are distinct positive integers, less than or equal to 10. The arithmetic mean of A and B is 9. The geometric mean of A and C is 6 . Find the harmonic mean of B and C. [6] Q.10 Express cos 5x in terms of cos x and hence find general solution of the equation cos 5x = 16 cos5x. [6] Q.11 If x is real and 4y2 + 4xy + x + 6 = 0, then find the complete set of values of x for which y is real. [6] Q.12 Find the sum of all the integral solutions of the inequality [6] 2 log3x – 4 logx27 5. 1 tan 1 tan 1 tan Q.13 If + + = , show that sin + sin + sin 1 = . 2 1+ tan 1+ tan 1+ tan cos + cos + cos Q.14(a) In any ABC prove that [7] c2 = (a – b)2cos2 C + (a + b)2sin2 C . 2 2 (b) In any ABC prove that a3cos(B – C) + b3cos(C – A) + c3cos(A – B) = 3 abc. [4 + 4] DPP-30 Q.1 8 clay targets have been arranged in vertical column, 3 being in the first column, 2 in the second, and 3 in the third. In how many ways can they be shot (one at a time) if no target below it has been shot. Q.2 Evaluate: x(sin2 (sin x) + cos2 (cos x))dx 0 Q.3 Evaluate: x(sin(cos2 x) cos(sin 2 x))dx 0 2 x 2 1 1 Q.4 dx Q.5 Prove that 3n +1 3n + 2 = 0 x sin x + cos x n=0 DPP-31 Q.1 If cos A, cos B and cos C are the roots of the cubic x3 + ax2 + bx + c = 0 where A, B, C are the angles of a triangle then find the value of a2 – 2b – 2c. Q.2 Find all functions, f : R R satisfying (x f (x) 2F(x))(F(x) x 2 ) = 0 x R where f (x) = F'(x). 2 x 1 1 2 Q.3 3 x dx 3 2 ln x Q.4 For a > 0, b > 0 verify that ax2 + bx + a dx reduces to zero by a substitution x = 1/t. Using this or ln x otherwise evaluate: x 2 + 2x + 4 dx tan1 x 3 Q.5 0 dx x DPP-32 0, Q.1 Evaluate: sin3 x cos x dx , x 2 Q.2 Evaluate: sin x