- #1
Anyiam
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1. Homework Statement
the Pth, Qth & Rth terms of an arithmetic sequence are in geometric progression. Show that the common ratio is (q-r)/(p-q) or (p-q)/(q-r).
2. Homework Equations
for an A.P, the Nth term=
a (n-1)d
for a G.P, the Nth term= ar^(n-1)
3. The Attempt at a Solution
let the Pth, Qth & Rth term be
p, q & r respectively. Since they are in A.P,
"d"= q-p = r-q
also, since they form a GP,
"r"= (p/q)or(q/p)= (r/q)or(q/r)
don't really know if to make the assumption that for this case, "d"= "r", is pretty safe!
So please what do i do next?
Thanks in anticipation!
the Pth, Qth & Rth terms of an arithmetic sequence are in geometric progression. Show that the common ratio is (q-r)/(p-q) or (p-q)/(q-r).
2. Homework Equations
for an A.P, the Nth term=
a (n-1)d
for a G.P, the Nth term= ar^(n-1)
3. The Attempt at a Solution
let the Pth, Qth & Rth term be
p, q & r respectively. Since they are in A.P,
"d"= q-p = r-q
also, since they form a GP,
"r"= (p/q)or(q/p)= (r/q)or(q/r)
don't really know if to make the assumption that for this case, "d"= "r", is pretty safe!
So please what do i do next?
Thanks in anticipation!