# The Binomial Theorem (VIDEO!)

Why is expanding a binomial of the form (x + y)^n connected with the n-th row of Pascal’s triangle? (For example, the coefficients that appear when expanding (x + y)^4 are 1, 4, 6, 4,1 and these represent the fourth row of the triangle.)

In this video we explain the connection and show how to have fun and prove mysterious properties of the triangle that you can invent for yourself!

WARNING: This video does rely on having seen the “A Formula for Pascal’s Triangle” video just so you know what the entries of Pascal’s triangle actually count.