"In Fig.  4.142, `P A ,\ Q B`and `R C`are each  perpendicular to `A C`. Prove  that `1/x+1/z=1/y`.
Channel: Doubtnut
Date: 2020-07-12

"In Fig.
  4.142, `P A ,\ Q B`
and `R C`
are each
  perpendicular to `A C`
. Prove
  that `1/x+1/z=1/y`
. (FIGURE)"