When white light is passed through a prism, which colour shows the minimum deviation?

If the refractive index of the material of a prism is $\cot(A/2)$,where $A$ is the angle of the prism,then the angle of minimum deviation will be:

$A$ thin prism $P_1$ with angle $4^o$ and made from glass of refractive index $1.54$ is combined with another thin prism $P_2$ made from glass of refractive index $1.72$ to produce dispersion without deviation. The angle of prism $P_2$ is......$^o$

$A$ ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to $3/4$ of the angle of the prism. The angle of deviation is......$^o$

$A$ prism is made up of a material with a refractive index of $\sqrt{3}$. The angle of the prism is $A$. If the angle of minimum deviation is equal to the angle of the prism, then the value of $A$ is: (in $^{\circ}$)

Derive the expression $\delta = i + e - A$ for a prism.