How do you find all the complex roots of x3x2+x1?

1 Answer
Feb 19, 2016

x=1,i,i

Explanation:

Step 1: Set the equation to equal to zero

x3x2+x1=0

Step 2: Group the terms like this

(x3x2)+(x1)=0

Step 3: Factor out the common like term for each group

x2(x1)+1(x1)=0
(x2+1)(x1)=0

Step 4 Set each factor equal to zero

x2+1 =0
1 1
x2 = 1
x2 =1

x=±i

or

x1=0
x=1

Answer: x=1,i,i