Question

Taking this quickcheck right now..
Find all the zeros of each equation
x3 – x2 + 5x – 5 = 0

a) isqrt5, –isqrt5, 1
b) isqrt5, –isqrt5, –1
c) sqrt5,-sqrt5, -1
d) isqrt5, 1

I suck at doing these. If you could show me the steps. I would appreiciate that.

Answer 1

Start by factoring: You'll get something like (x-1)(x^2+5)=0
now solve each:
(x-1)=0
(x^2+5)=0... solve this one using the quadratic formula.

Answer 2

Start by solving the firt equation:
(x-1)=0
x-1=0
x=1
now solve the second equation.
(x^2+5)=0
x^2+5=0
subtract the 5
x^2=-5
take the square root of both sides....(no need to really use the quadratic formula).
x=-sqrt5, x=-(isqrt5), x=1

Answer 3

Oh ok I was confused on what the first step should be. So you factor first.. Ok. Thanks.