Answer:
x = 1 or x = ± i
Step-by-step explanation:
Note the sum of the coefficients
1 - 1 + 1 - 1 = 0
This indicates that x = 1 is a root, thus (x - 1) is a factor
Using long division or synthetic division, then
x³ - x² + x - 1 = (x - 1)(x² + 1), thus
(x - 1)(x² + 1) = 0
Equate each factor to zero and solve for x
x - 1 = 0 ⇒ x = 1
x² + 1 = 0 ⇒ x² = - 1 ⇒ x = ± = ± i
Given:
The equation is
To find:
The number of roots and discriminant of the given equation.
Solution:
We have,
The highest degree of given equation is 2. So, the number of roots is also 2.
It can be written as
Here, .
Discriminant of the given equation is
Since discriminant is , which is greater than 0, therefore, the given equation has two distinct real roots.