## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

the zeros are $x=-4$ or $x=4$ and the $x$-intercepts are $(-4,0)$ and $(4,0)$.
By factorization, we have $$P(x)=3x^2-48=3(x^2-16)=3(x+4)(x-4) .$$ That is, we have $x+4=0$ or $x-4=0$. So the zeros are $x=-4$ or $x=4$ and the $x$-intercepts are $(-4,0)$ and $(4,0)$.