| If the equation cos x + 3 cos (2Kx) = 4
has exactly one solution, then
(1) K is a rational number of the form
(P/(P + 1)), P ≠ −1
(2) K is irrational number whose
rational approximation does not
exceed 2
(3) K is irrational number
(4) K is a rational number of the form
(P/(P − 1)), P ≠ 1
|