(Choose 1 answer)
(See picture)
A. (iii)
B. (ii)
C. (i)
D. (iv)
In the inductive proof of the proposition
"12+22+ ... + n²=n(n+1)(2n+1)/6 for all n≥1",
which of the following equations is used?
(i) 12+22+...+ (k+1)2=k(k+1)(2k+1)/6+k²+1
(ii) 12+22+...+ (k+1)2=k(k+1)(2k+1)/6+ (2k+1)
(iii) 12+22+ ... + (k+1)2=k(k+1)(2k+1)/6+ (k+1)2
(iv) 12+22+ ... + (k+1)2=k(k+1)(2k+1)/6+k2
