Please look at the conditions and say that θ is a root of the cubic polynomial f (x) = x3-3x+ 10, instead of f (x) = 0, which will solve the problem well.

You can set h(x)=px2+qx+r, and the topic becomes the value of r, that is, when α=0, θ =? problem h(0)=r

If α=0, θ= 1 or -2 can be obtained. Note that p is a rational number.

It is easy to know that when θ= 1, P is an irrational number, and P can be found, but it is not necessary as a multiple-choice question.

(The inspection process is omitted, and it must be noted that θ is the root of the cubic polynomial f (x) = x3-3x+ 10, not the root of f (x) = 0).