Answer:
a = 2, b = -1
Explanation:
p(x) = ax³ + x² - 2x + b
p(1) = a(1)³ + 1² - 2•1 + b = a + 1 - 2 + b = a + b - 1
a + b - 1 = 0 ⇒ b = 1 - a
p(-1) = a(-1)³ + (-1)² - 2(-1) + b = -a + 1 + 2 + b = - a + b + 3
- a + b + 3 = 0 ∧ b = 1 - a
- a + (1 - a) + 3 = 0
- a + 1 - a + 3 = 0
-2a + 4 = 0
-2a = -4
a = 2
b = 1 - 2 = -1