Review question

# How are the $p$th, $q$th and $r$th terms of an AP related? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R6137

## Question

The $p$th term of a progression is $P$, the $q$th term is $Q$, and the $r$th term is $R$. Show that, if the progression is arithmetical, $P(q-r)+Q(r-p)+R(p-q)=0$ and that, if it is geometrical, $(q-r)\log P+(r-p)\log Q+(p-q)\log R=0.$