A couple days ago we have went over Pascal's Triangle and Binomial Theorem.
Pascal's Triangle is a table of Binomial Coefficients.
<--------- (x + y)0 = 1
<--------- (x + y)1 = 1x+1y
<----------(x + y)² = 1x + 2xy +1y
<----------(x + y)3 = 1x + 3x y + 3x y + 1y
<----------(x + y)4 = 1x + 4xy + 6xy + 3xy + 1y
Binomial Theorem is a formula to quickly expand binomial expressions to locate a specific term.
Formula: Tk+1=nCk A^n-k B^k
Example 1 Using the formula to find the 4th term of (x-2y)^10
K= 4-1 = 3 Tk+1=nCk A^n-k B^k
N= 10 T3+1=10C3 (x)^10-3 (-2y)^3
A= X
B= -2y T4= 120 * x^7 * -8y^3
T4= -960x^7y^3