graph the function f(x)=(x+1)(x-2)
f(x) = (x + 1)(x - 2)f(x) = x(x - 2) + 1(x - 2)f(x) = x(x) - x(2) + 1(x) - 1(2)f(x) = x² - 2x + x - 2f(x) = x² - x - 2
