抛物线Y^2=2PX,过点A(8,-8),则点A到抛物线的焦点距离为多少
问题描述:
抛物线Y^2=2PX,过点A(8,-8),则点A到抛物线的焦点距离为多少
答
Y^2=2PX,过点A(8,-8),代入得p=4,Y^2=8x,准线为x=-2
点A到抛物线的焦点距离=点A到抛物线的准线距离=8-(-2)=10