SOLUTION: Somehow my jamielee90@ymail.com address doesnt seem to be working since I never seem to recieve a msg's from this site, on that account, so I asked a friend to make me an account o

Algebra.Com
Question 199208: Somehow my jamielee90@ymail.com address doesnt seem to be working since I never seem to recieve a msg's from this site, on that account, so I asked a friend to make me an account on his, hope it goes through now =/
Ok so to the real problem, I dont get how to solve these problems, could someone help me out here?
1)Find a quadratic equation with roots (4+i) and (4-i).
2)Find the irrational roots of x^3-4x^2+2x+1=0 (I should also use the quadratic formula to solve it)
3) x^3-2x^2+x-3=0 what are the possible rational roots?
As you might see I am not too good with roots, I never really have been =(

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
or Start with the given solutions.


or Subtract 4 from both sides (for each equation).


or Square both sides


or Square i to get -1 and square -i to get -1


or Add 1 to both sides.


Since the equations are the same, we can focus on one equation:





FOIL


Combine like terms.


So the quadratic with the roots 4+i and 4-i is





# 2


First, let's find the possible rational zeros


Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 1 (the last coefficient):



Now let's list the factors of 1 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur




Let's see if the possible zero is really a root for the function


So let's make the synthetic division table for the function given the possible zero :
1|1-421
| 1-3-1
1-3-10

Since the remainder (the right most entry in the last row) is equal to zero, this means that is a zero of

Take note that the first three values in the bottom row are 1, -3, and -1. So this means that





Now all we need to do is solve to find the next two zeros:


Notice we have a quadratic in the form of where , , and


Let's use the quadratic formula to solve for "x":


Start with the quadratic formula


Plug in , , and


Negate to get .


Square to get .


Multiply to get


Rewrite as


Add to to get


Multiply and to get .


or Break up the expression.


So the next two zeros are or


===================================================================================

Answer:

So the three roots are , or


where the irrational roots are and







# 3

Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of -3 (the last coefficient):



Now let's list the factors of 1 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur



RELATED QUESTIONS

S = S subscript 0 + V subscript 0 t - 16t^2. Where S represents the objects height off... (answered by scott8148)
If operation 'o' is unknown and, a 'o' b = a + 2b ; and, 3 'o' X = 4 ; what is variable... (answered by ankor@dixie-net.com)
HOW TO DO SURFACE AREA ON A RECTANGULAR PRISM WHEN OVERLAPPED ? our teacher doesnt... (answered by JBarnum)
I can't seem to get to solve this proof. 1. W->S 2. U->F 3. (S and F) -> O 4. ~O... (answered by jim_thompson5910)
Hi I am sorry, I am truly sorry, I only resubmitting this because this is my first... (answered by mananth)
I have been working on solving linear systems I cannot figure out where to move and... (answered by askme)
ok this is it,how many pounds of seed worth 60 cents must be mixed with 300 pounds of... (answered by Nate)
I never seem to be able to set up equations from story problems. I think I have an idea... (answered by ankor@dixie-net.com)
Point P(u, v) is in the first quadrant on the graph of the line connecting the points... (answered by ikleyn)