Question: i need help with these please problem 4 calculate 1...
I need help with these please.
1 + 2 + 3 + ··· + 98 + 99 + 100
by deriving a general formula for . To that end start with the conjectural form for Sn = an2 + bn + c with some unknown a,b,c and then fix these coefficients by considering Sn for different values of n.
Check the expression for
by showing that (1 + x) × (1 + x)a = (1 + x)a+1. If the case of general a poses challenge, check this expression for a = 3.