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

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

If (3+2i sintheta)/(1-2i sintheta) is a real number and 0lt theta lt 2pi , then theta is a. pi \ b. pi/2 \ c. pi/3 \ d. pi/6

Let vectors vec a , vec b , vec c ,a n d vec d be such that ( vec axx vec b)xx( vec cxx vec d)=0. Let P_1a n dP_2 be planes determined by the pair of vectors vec a , vec b ,a n d vec c , vec d , respectively. Then the angle between P_1a n dP_2 is a.0 b. pi//4 c. pi//3 d. pi//2

If f(x)=e^xsinx in [0,\ pi] , then c in Rolles theorem is pi//6 (b) pi//4 (c) pi//2 (d) 3pi//4

For f(x)=sin^2x ,x in (0,pi) point of inflection is: pi/6 (b) (2pi)/4 (c) (3pi)/4 (d) (4pi)/3

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