If the angle between the vectors and is obtuse and
MATHEMATICS · Single correct · AP · AP Precalculus · Functions with Parameters, Vectors, and Matrices · Functions with Parameters, Vectors, and Matrices
Problem
If the angle between the vectors a=i^+(cosx)j^+k^ and b=(sin2x−sinx)i^−(cosx)j^+(3−4sinx)k^ is obtuse and x∈(0,2π) , then the exhaustive set of values of ' x ' is equal to
(1) x∈(0,6π)
(2) x∈(6π,2π)
(3) x∈(6π,3π)
(4) x∈(3π,2π)