共50条信息
在平面直角坐标系\(xoy\)中,点\(A(0,3) \),直线\(l:y=x-2\)\(.\)设圆\(C\)的半径为\(1\),圆心在\(l\)上\(.\)
\((1)\)若圆心\(C\)也在直线\(y=\dfrac{1}{2}x\)上,过点\(A\)作圆\(C\)的切线,求切线的方程;
\((2)\)设圆心\(C\)的横坐标为\(a\)\(\left( a > 0 \right)\),若圆\(C\)上存在点\(M\),使\(\sqrt{2}MA=\sqrt{5}MO\),求\(a\)的取值范围.
在平面直角坐标系\(xoy\)中,圆\(C\)的方程为\({{x}^{2}}+{{y}^{2}}-4x+2y=0\),若直线\(y=3x+b\)上存在一点\(P\),使过\(P\)所作的圆的两条切线相互垂直,则实数\(b\)的取值范围是______
已知直线\(x-y+1=0\)与圆\(C\):\({{x}^{2}}+{{y}^{2}}-4x-2y+m=0\)交于\(A,B\)两点.
\((1)\)求线段\(AB\)的垂直平分线的方程;
\((2)\)若\(\left| AB \right|=2\sqrt{2}\),求\(m\)的值;
\((3)\)在\((2)\)的条件下,求过点\(P(4,4)\)的圆\(C\)的切线方程.
已知动圆\(C:{\left(x-m\right)}^{2}+{\left(y-2m\right)}^{2}={m}^{2}\left(m > 0\right) \)
\((\)Ⅰ\()\)当\(m=2 \)时,求经过原点且与圆\(C\)相切的直线\(l\)的方程;
\((\)Ⅱ\()\)若圆\(C\)与圆\(E:{\left(x-3\right)}^{2}+{y}^{2}=16 \)内切,求实数\(m\)的值.
已知直线\(x-y+1=0\)与圆\(C\):\(x^{2}+y^{2}-4x-2y+m=0\)交于\(A\),\(B\)两点;
\((2)\)若\(|AB|=2\),求\(m\)的值;
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