1. a Show that (x+1)3=x3+3x2+3x+1 .
2. b Copy and complete:
(0+1)3=03+3(0)2+3(0)+1(1+1)3=13+3(1)2+3(1)+1(2+1)3=23+…(3+1)3=…⋮(n+1)3=…
(a) Show that (x+1)3=x3+3x2+3x+1 .
(b) Copy and complete:
(0+1)3=03+3(0)2+3(0)+1(1+1)3=13+3(1)2+3(1)+1(2+1)3=23+…(3+1)3=…⋮(n+1)3=…
(c) Add the terms vertically, and hence show that (n+1)3=3∑k=1nk2+3∑k=1nk+(n+1) .
(d) Given that ∑k=1nk=2n(n+1) , show that ∑k=1nk2=6n(n+1)(2n+1) .