Answer:
Step-by-step explanation:
A) (f(x) - f(a)) / (x - a)
(3x²– 4x – 8 - (3a² – 4a – 8)) / (x - a)
(3x²– 4x – 8 - 3a² + 4a + 8) / (x - a)
(3(x² - a²) – 4(x - a)) / (x - a)
(3(x - a)(x + a) – 4(x - a)) / (x - a)
3(x + a) - 4
B) (f(x + h) - f(x)) / h
(3(x + h)² - 4(x + h) - 8 - (3x² - 4x - 8)) / h
(3(x² + 2xh + h²) - 4x - 4h - 8 - 3x² + 4x + 8) / h
(3x² + 6xh + 3h² - 4x - 4h - 8 - 3x² + 4x + 8) / h
(3x² + 6xh + 3h² - 4h - 8 - 3x² + 8) / h
(3x² + 6xh + 3h² - 4h - 3x² ) / h
( 6xh + 3h² - 4h ) / h
(6xh + 3h² - 4h) / h
6x + 3h - 4
