LEVEL-1 1. Find the domain of definition of f(x) = cos(x2 - 4). 2. Find the domain of f(x) = 2 cos-12x + sinx. 3. Find the domain of f(x) = cos x + cos x. 4. Find the principal value of each of the following: (i) cos-11-13) [NCERT] [NCERT) (ii) cos-1(12) (iv) cos-1( tan ) 5. For the principal values, evaluate each of the following: [NCERT, CBSE 2012] (1) cos?+ 2 sin -- 2 (ii) cos-()-2-in-1 (23) (ii) sin--( - )+2c08-1(-3) [CBSE 2012]