Question #9c3e2

1 Answer
Feb 14, 2017

{-3,-1/2}{3,12}

Explanation:

If 1/212 and 33 are zeroes then y=4x^4-37x^2+9=p_2(x)(x-1/2)(x-3)y=4x437x2+9=p2(x)(x12)(x3) where p_2(x)=a x^2+bx+cp2(x)=ax2+bx+c is a generic order 22 polynomial.

Substituting and equating coefficients we have

4x^4-37x^2+9=(ax^2+bx+c)(x-1/2)(x-3)4x437x2+9=(ax2+bx+c)(x12)(x3)

so

{((3 c)/2=9),(-(3 b)/2 + (7 c)/2=0),( - (3 a)/2 + (7 b)/2 - c=37),((7 a)/2 - b=0),(a=4):}

now solving for a,b,c we obtain

a = 4, b = 14, c = 6

so p_2(x)=4x^2+14x+6 with roots

x={-3,-1/2} so finally

y=4x^4-37x^2+9=4(x^2-3^2)(x^2-(1/2)^2)