Let Sini = a, I = Arcsina and Cosi = √ (1-A 2).

sinicosφ/[ 1-cos(I-φ)]= cosφ* a/[ 1-cosicosφ-sinisinφ]

=cosφ*a/[ 1-√( 1-a^2)cosφ-asinφ]=γh/( 16c^2)

Then do the math yourself. Solution A is a bit complicated and simple.