SOLUTION: Make up a polynomial that meets the following conditions: a)it has rational zeros 3/4 and -1/3 b)it has two complex roots of the form a+bi,a,b "not equal" to 0 Then, create the

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Make up a polynomial that meets the following conditions: a)it has rational zeros 3/4 and -1/3 b)it has two complex roots of the form a+bi,a,b "not equal" to 0 Then, create the       Log On


   



Question 390785: Make up a polynomial that meets the following conditions:
a)it has rational zeros 3/4 and -1/3
b)it has two complex roots of the form a+bi,a,b "not equal" to 0
Then, create the list of all possible rational roots and use synthetic division to reduce the 4th degree polynomial to a quadratic and solve for the remaining roots. Show all steps.

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
There's an important theorem called "The Fundamental Theorem of Algebra" (it looks easy, but requires high-level analysis to prove) that says that any n-degree polynomial has n roots, counting multiplicities.

Furthermore, if r is a root of the polynomial, then (x-r) is a factor of it (this will be useful in generating the polynomial).

Therefore the polynomial P(x) is equal to

P%28x%29+=+%28x-3%2F4%29%28x%2B1%2F3%29%28x+-+a+-+bi%29%28x+-+a+-+bi%29

You write in your problem "Then, create the list of all possible rational roots and use synthetic division to reduce the 4th degree polynomial to a quadratic and solve for the remaining roots. Show all steps." However, the only rational roots are 3/4 and -1/3. The quadratic with a double root x - a - bi has double root a+%2B+bi. Therefore, solving for the remaining roots using synthetic division is unnecessary...only do that if you're practicing your synthetic division :)