>>12142657>If you've done a proof by induction you should know this"Proof by induction" and "inductive argument" are two totally different things.
OP's pic has nothing whatsoever to do with proof by induction.
Proof by induction is when you prove f(n) based on the assumption that f(n-1) is true, using a formula that relates f(n) with f(n-1).
For example, if you look at these two properties of the triangular numbers:
T(0) = 0
and
T(n) = T(n-1) + n (for integer n > 0)
then, together, these can be used to show that:
T(n) = (n(n+1))/2
using proof by induction.
