A prism of refractive index n and length A is placed in minimum deviation position. If the angle of minimum deviation is equal to the angle A, then the value of A is :
(a) sin^-1(n/2)
(b) 2sin^-1((n/2)^½)
(c) 2sin^-1((1-(n)^2 /2)^½)
(d) 2sin^-1[(4-n^2/4)^½]
