to start with I am new to this forum and I come from sweden so I am not that good in english mathematic terms. But I will try my best. Also I am going in highschool and not college/university but sinse the course I am taking is named "Descrete mathe" I thought it would fit quiet good here. Anyway, I think this is very easy but I am in year 1 in highschool so for me it's hard.
I need to prove that n = 1,2,3 ...
is working for
a) 2 + 4 +...+ 2n = n(n+1)
b) 1 + 2 + 4 +...+ 2^n = 2^(n+1)-1
I cant even figure out the A..
This is how I do it, please help me !
n=1 VL=2, HL=1(1+1)=2, VL=HL
2 + 4 +...+ 2p = p(p+1)
2 + 4 +...+ 2p + (2p+1) = (p+1)(p+2)
p(p+1)+(2p+1) = (p+1)(p+2)
p^2+p+2p+1 = p^2+p+2p+2
Now why is that wrong, I am doing something wrong..