Pre-Calculus Section 8.5a Binomial Expansion
Calculator Help Graphing calculator has n C r button. Math - PRB - nCr You must enter the n# before
Remember? (x + y) 0 (x + y) 1 (x + y) 2 (x + y) 3
Binomial Theorem Expands a binomial to any power (x + y) n = x n + nx n-1 y + …. + n C r x n-r y r +….nxy n-1 + y n * there are n + 1 terms * the power of the first term = n * the power of the last term = n
* the power of the rest of the terms decreases by 1 from left to right * the power of the rest of the terms decreases by 1 from right to left * the exponents add to equal n * find the coefficients using n C r * if subtracting alternate the signs
Write the expansion of (x + 2) 3 Binomial Expansion Coefficients: n = exponent the first term has a power of 3 3 C 0 = 1 st coefficient 3 C 1 = 2 nd coefficient 3 C 2 = 3 rd coefficient 3 C 3 = 4 th coefficient
5.Write the expansion of (x + 2) 3
6.Write the expansion of (y - 7) 4
7.Write the expansion of (x + y) 5
8.Write the expansion of (3x + 2y) 6
Homework: Page – 10Evens 18 – 26Evens