What is the first step to prove that Sn => 2+4+6 ....+2n=n(n+1)
a. Verify that Sn is valid for n=1
b. Assume that Sn is valid for n=k
c. Show that Sn is valid for n =k
d. Prove that Sn is valid for n=k+1
I thought it was d? correct me if im wrong
thanks.