Pascal’s Triangle and Binomial Expansion (Leaving Cert Mathematics): Flashcards

Rows start & end with 1; each other number is sum of two numbers above it

With 1

Sum of two numbers directly above

Find coefficients in binomial expansion

Coefficients in $(a+b)^n$ expansion

Writing expressions without full multiplication

$\binom{n}{r}x^{n-r}y^r$

Powers in each term must add to $n$

2 (since $5+2=7$)

$r=5$ (starts at 0)