1 problem

Let $F:\mathbb{C}^4\rightarrow\mathbb{C}^4$ be the birational map … let $\phi(x_1,x_2,x_3,x_4)=x_1x_4-x_2x_3$, and for generic $c\in\mathbb{C}$ let $X_c\subset\mathbb{P}^4$ be the…