Hello again, hats_06!
I must assume you know the routine for an inductive proof.
Verify . . . True!Prove by induction: .
Assume is true: .
Add to both sides:
. .
The right side is: .
Factor: .
. . .
We have proved
. . The inductive proof is complete.
Ha! . . . Dan beat me to it (again) . . .
.