If cos-1 x/2 + x/2 + cos-1 y/3 = θ then the value of 9x2 - 12xy cosθ + 4y2 is equal to N sin2 θ (where N is a positive integer) and complete set of values of x for which (cos-1 x)2 (sin -1 x) 2 > 0 is satisfied, is [p, q).
1. Which of the following values lie in [p, q) ?
(A) √N - 3
(B) √N - 4
(C) √N - 5
(D) √N - 6
2. Which of the following functions cannot be defined at x = √N - 6 ?
(A) sin-1 x
(B) cos -1 x
(C) tan -1 x
(D) sec -1