Expand (x+1)3Using an Identity
Given: (x+1)3
We know that (x+y)3=x3+y3+3xy(x+y).
Now, substitute y=1 in the above formula, we get;
⇒(x+1)3=x3+13+3(x)(1)(x+1)
⇒(x+1)3=x3+3x2+3x+1.
Hence, expansion of (x+1)3is x3+3x2+3x+1.