A problem from the chapter 'theory of equations' Question : Form a biquadratic equation with rational coefficients two of whose roots are √3 + 2 and √3 - 2. 
So f(x) = (x- √3-2)(x-√3+2)q(x) where q(x) must be a quadratic equation. This is how far I have done. But I cannot solve it. I am a Bsc student with maths as an ancillary paper. Help would be appreciated.

Write a quadratic equation which has roots $x_1=\left(\sqrt{3}+2\right)^2=7+4 \sqrt{3};\;x_2=\left(\sqrt{3}-2\right)^2=7-4 \sqrt{3}$
We need the sum and the product of the roots
$x_1+x_2=14;\;x_1x_2=\left(7+4 \sqrt{3}\right)\left(7-4 \sqrt{3}\right)=1$
$$(x-x_1)(x-x_2)=x^2-(x_1+x_2)x+x_1x_2=x^2-14x+1$$
And then substitute $x$ with $x^2$
$$x^4-14x^2+1=0$$
