`prod_(k=0)^3 (1+cos\ ((2k+1)pi)/8)=` (A) `1/16` (B) `-1/8` (C) `1/8` (D) 1

The value of prod_(k=0)^6 sin\ ((2k+1)pi)/14= (A) 1/16 (B) 1/64 (C) 1/32 (D) none of these

Cube of (-1)/2i s 1/8 (b) 1/(16) (c) -1/8 (d) (-1)/(16)

prod_ (k = 1) ^ (6) (sin ((2k pi) / (7)) - i cos ((2k pi) / (7))) =

If z^(7)+1=0 then cos((pi)/(7))cos((3 pi)/(7))cos((5 pi)/(7)) is (A)(1)/(8) (B) -(1)/(8)(C)(1)/(2sqrt(2))(D)(1)/(2)

((144)^(1/2)+(256)^(1/2))/(3^2-2) = (A) 8 (B) 4 (C) -4 (D) -8

The value of sum_(r=0)^(10)cos^(3)((r pi)/(3)) is equal to (a) (1)/(4) (b) (1)/(8)(c)-(1)/(4)(d)-(1)/(8)

If int(cos4x+1)/(cotx-tanx)dx=kcos4x+c , then k= (A) -1/4 (B) -1/2 (C) -1/8 (D) none of these

prod_ (n = 1) ^ (6) (1 + tan ((n pi) / (16))) (1 + tan (((3ln + 4) pi) / (16)))

(1 + cos ((pi) / (8))) (1 + cos (3 (pi) / (8))) (1 + cos (5 (pi) / (8))) (1 + cos (7 (pi) / (8))) =

If X is a random variable with probability distribution as given below: X=x_i : 0 1 2 3 P(X=x_i): k 3k 3k k The value of k and its variance are (A) 1/8, 22/27 (B) 1/8, 23/27 (C) 1/8, 24/27 (D) 1/8,3/4