Respuesta :
Answer:
Given function:
- f(x) = x³ + x² - 8x - 6
This is the third degree polynomial, so it has total 3 roots.
Lets factor it and find the roots:
- x³ + x² - 8x - 6 =
- x³ + 3x² - 2x² - 6x - 2x - 6 =
- x²(x + 3) - 2x(x + 3) - 2(x + 3) =
- (x + 3)(x² - 2x - 2) =
- (x + 3)(x² - 2x + 1 - 3) =
- (x + 3)((x - 1)² - 3) =
- (x + 3)(x - 1 + √3)(x - 1 - √3)
The roots are:
- x = -3
- x = 1 - √3
- x = 1 + √3
It has highest degree 3 so 3 roots
- 1 positive and 2 negative roots
Lets find
- x³+x²-8x-6=0
- x²(x+3)-2x(x+3)-2(x+3)=0
- (x+3)(x²-2x-2)=0
- (x+3)(x-2.732)(x+0.732)=0
Roots are
- -3,2.732,-0.732