If y is the mean proportional between x and z, prove that : x2−y2+z2x−2−y−2+z−2=y4
Given.
y is mean proportion between x and z
so
y2=xz
we have to prove that
(x2−y2+z2)(x−2−y−2+z−2)=y4
Taking L. H. S we have
→(x2−y2+z2)(x−2−y−2+z−2)
→x2+y2+z21x2+1y2+1z2
→x2−xz+z21x2−1xz+1z2
→x2−xz+z2z2−xz+z2
→x2z2
→(xz)2
→(y2)2
→y4=R.H.S