If p,q,r are in A.P. and x,y,z are in G.P. ,prove that xq-ryr-pzp-q=1.
p,q,r are in AP so 2q = p+r
and x,y ,z are in gp so y2 = xz
now xq-r yr-p zp-q = x(p+r / 2 - r ) yr-p z(p - (p- r)/2 )
=x(p- r/2). y r-p z(p-r/2)
= x(p- r/2). (xz) (r-p)/2 z(p-r/2)
= x(p- r/2). x (r-p/2) z(r-p/2) z(p-r/2)
= x0 z0
=1