Observe the following statements 
Assertion (A) : The general solution for $\cos \theta =\frac{3}{2} is \theta =2n\pi \pm {\cos }^{-1}(3/2)$
Reason (R) : The general solution for cos$\theta$=k is $\theta =2n\pi \pm \alpha , n\in Z$ where  $\alpha$ is principal value, $\alpha \in [0,\mathrm{\pi }] and \left|k\right| < 1.$

Then the true statement among the following is