SOLUTION: write a polynomial function of the least degree that has rational coefficients, a leading coefficient of 1 and the given zeros. zeros are 3 and 1-square root of 3. f(x) = (x-3)*

Algebra ->  Rational-functions -> SOLUTION: write a polynomial function of the least degree that has rational coefficients, a leading coefficient of 1 and the given zeros. zeros are 3 and 1-square root of 3. f(x) = (x-3)*      Log On


   



Question 1057542: write a polynomial function of the least degree that has rational coefficients, a leading coefficient of 1 and the given zeros. zeros are 3 and 1-square root of 3.
f(x) = (x-3)*(x-1-sqr root3)*(x-1+sq rt 3)
not sure how to proceed from here

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
%22f%28x%29%22%22%22=%22%22%28x%5E%22%22-3%29%28x%5E%22%22-1-sqrt%283%29%29%2A%28x%5E%22%22-1%2Bsqrt%283%29%29
Start by putting in some inner parentheses in the last two factors:

%22f%28x%29%22%22%22=%22%22

Now multiply the last two parentheses using FOIL.  When you do,
the "Inner" and "Outer" terms will cancel out: 

%22f%28x%29%22%22%22=%22%22%28x%5E%22%22-3%29%28%28x-1%29%5E2%2Bsqrt%283%29%28x-1%29-sqrt%283%29%28x-1%29-3%29

%22f%28x%29%22%22%22=%22%22

In fact we could have skipped that and gone straight to:

%22f%28x%29%22%22%22=%22%22%28x%5E%22%22-3%29%28%28x-1%29%5E2-3%29

Now use FOIL again:

%22f%28x%29%22%22%22=%22%22x%28x-1%29%5E2-3x-3%28x-1%29%5E2%2B9%29

Now simplify %28x-1%29%5E2=%28x-1%29%28x-1%29=x%5E2-x-x%2B1=x%5E2-2x%2B1 <--FOIL again!

%22f%28x%29%22%22%22=%22%22x%28x%5E2-2x%2B1%29-3x-3%28x%5E2-2x%2B1%29%2B9%29

%22f%28x%29%22%22%22=%22%22x%5E3-2x%5E2%2Bx-3x-3x%5E2%2B6x-3%2B9%29

%22f%28x%29%22%22%22=%22%22x%5E3+-+5x%5E2+%2B+4x+%2B+6

Edwin