If `P(0,1,2),\ Q(4,-2,1)a n d\ O(0,0,0)` are three points then `angle P O Q=` a. `pi/6` b. `pi/4` c. `pi/3` d. `pi/2`

If P(0,1,2),Q(4,-2,1) and O(0,0,0) are three points, then /_POQ=

If P(0,1,2),Q(4,-2,1) and O(0,0,0) are three points then POQ=(pi)/(6) b.(pi)/(4) c.(pi)/(3) d.(pi)/(2)

If P = (0,1,2) and Q = (4,-2,1), O = (0,0,0) then P hat O Q =

If A=(1,0,1), B=(0,-1,0), C=(-1,0,1), D=(0,1,-1) then angle between vec(AB) and vec(CD) is (A) pi/6 (B) pi/4 (C) pi/3 (D) pi/2

int_0^(pi//2)xsinx\ dx is equal to a. pi//2 b. pi//4 c. pi d. 1

If tanA=a/(a+1) and tanB=1/(2a+1) then the value of A+B is: (a). 0 (b). pi/2 (c). pi/3 (d). pi/4

The value of int_0^pi1/(5+3cosx)dx is a. pi//2 b. pi//4 c. 0 d. pi//8

If 3p + 2q = i + j + k and 3p -2q =i-j-k , then the angle between p and q is a) pi/6 b) pi/4 c) pi/3 d) pi/2

The value of int_0^pi1/(5+3cosx)dx is pi//2 b. pi//4 c. 0 d. pi//8

P and Q are points on the ellipse x^2/a^2+y^2/b^2 =1 whose center is C. The eccentric angles of P and Q differ by a right angle. If /_PCQ minimum, the eccentric angle of P can be (A) pi/6 (B) pi/4 (C) pi/3 (D) pi/12