Answer:
x = 2, x = 8
Step-by-step explanation:
reminder that f'(x) = [tex]m_{tangent}[/tex]
Differentiate f(x) term by term using the power rule
[tex]\frac{d}{dx}[/tex] (a[tex]x^{n}[/tex] ) = na[tex]x^{n-1}[/tex]
f(x) = [tex]\frac{1}{3}[/tex] x³ - 5x² + 2x + 10
f'(x) = x² - 10x + 2
Equating f'(x) to - 14
x² - 10x + 2 = - 14 ( add 14 to both sides )
x² - 10x + 16 = 0 ← in standard form
(x - 2)(x - 8) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 2 = 0 ⇒ x = 2
x - 8 = 0 ⇒ x = 8
