共50条信息
已知点\(P(1,0)\),抛物线\({{y}^{2}}=2px(p > 0)\)与直线\(y=x+1\)交于\(A,B\)两点,\(PA\)所在直线为\({{l}_{1}}\),\(PB\)所在直线为\({{l}_{2}}\),\({{l}_{1}}\)与\({{l}_{2}}\)的斜率之积为\(-2\),则此抛物线的方程为
抛物线\(y=x^{2}\)上一点到直线\(2x-y-4=0\)的距离最短的点的坐标是\((\) \()\)
直线\(y=kx+2\)与抛物线\(y^{2}=8x\)有且只有一个公共点,则\(k\)的值为\((\) \()\).
若直线与抛物线只有一个交点,则直线与抛物线一定相切\(.\)( )
焦点为\(F\)的抛物线\(C\):\(y^{2}=8x\)的准线与\(x\)轴交于点\(A\),点\(M\)在抛物线\(C\)上,则当\(\dfrac{|MA|}{|MF|}\)取得最大值时,直线\(MA\)的方程为
过点\(M(1,0)\)作斜率为\(1\)的直线\(l\)交抛物线\(y^{2}=4x\)于\(A\),\(B\)两点,则\(|AB|=\)
已知直线\(x-y+1=0\)与抛物线\(y=ax^{2}\)相切,则\(a=\)________.
过抛物线\(x\)\(=4\)\(y\)的焦点作直线交抛物线于\(A(\)\(x\)\({\,\!}_{1}\),\(y\)\({\,\!}_{1})\)和\(B(\)\(x\)\({\,\!}_{1}\),\(y\)\({\,\!}_{2})\)两点,若\(y\)\({\,\!}_{1}+\)\(y\)\({\,\!}_{2}=6\),则线段\(AB\)的长是__________\(.\)
已知抛物线\(C\):\(y\)\({\,\!}^{2}=8\)\(x\),\(O\)为坐标原点,直线\(x\)\(=\)\(m\)与抛物线\(C\)交于\(A\),\(B\)两点,若抛物线\(C\)的焦点\(F\)恰好为\(\triangle \)\(OAB\)的重心,则线段\(AF\)的长为________.
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