So is it only this I need to know about binomial theorem?

Here are some other important concepts:

• Finding a Specific Term: You can find any particular term in an expansion without writing out the entire series. The $(r+1)$-th term in the expansion of $(a+b)^n$ is given by $T_{r+1} = \binom{n}{r} a^{n-r} b^r$.
• Binomial Series (for non-integer exponents): The theorem can be extended to cases where $n$ is a negative integer or a fraction. In these cases, the expansion results in an infinite series, and it's valid only for certain ranges of $a$ and $b$ (e.g., $|b/a| < 1$).
• Properties of Binomial Coefficients: There are many identities and relationships involving binomial coefficients, such as Pascal's Triangle, which provides a visual way to generate them.