Question

Question 3 (4 points) Use FOIL to derive the identify for (a - b)2.

Answer 1

Foil is the math standard for the multiplication of polynomials. So

(a - b)² = (a - b)*(a - b) = a*a + a*(-b) - b*a - b*(-b) = a² -ab - ab + b² = a² - 2ab + b²