X - Intercept: f(x) = x³ + 2x ²- 9x - 18
0 = x³ + 2x² - 9x - 18
0 = x²(x) + x²(2) - 9(x) - 9(2)
0 = x²(x + 2) - 9(x + 2)
0 = (x² - 9)(x + 2)
0 = (x² - 3x + 3x - 9)(x + 2)
0 = (x(x) - x(3) + 3(x) - 3(3))(x + 2)
0 = (x(x - 3) + 3(x - 3))(x + 2)
0 = (x + 3)(x - 3)(x + 2)
x + 3 = 0 or x - 3 = 0 or x + 2 = 0
- 3 - 3 + 3 + 3 - 2 - 2
x = -3 x = 3 x = -2
Solution set: {±3, -2} or {-3, 3, 2}
Y - Intercept: f(x) = x³ + 2x² - 9x - 18
f(x) = (0)³ + 2(0)² - 9(0) - 18
f(x) = 0 + 2(0) - 0 - 18
f(x) = 0 + 0 - 18
f(x) = 0 - 18
f(x) = -18
