1×1!+2×2!+3×3!+…+k×k!(k≥4)的末位数字是__.
若关于x的不等式2kx2>(x-2)2恰有4个整数解,则实数k的取值范围是___.
已知集合A={x|x2-2014x+2013<0},={x|log2x
}(m∈n∗),若a⊆b,则m的最小值是__.
设f(x)是R上的减函数,且f(0)=3,f(3)=-1.已知P={x||f(x+t)-1|
如图1,三棱锥A-BCD的顶点B、C、D在平面α内,CA=AB=BC=CD=DB=2,AD=6.若将该三棱锥以BC为轴转动,到点A落到平面α内为止,则
A、D两点所经过的路程之和是___.
As shown in Fig.3, AB=6, BC=8, CA=10. Point P is inside of the triangle ABC. DE, FG, and IH all pass point P and are parallel to AB, BC, and CA, respectively. The lengths of DE, FG and IH are all equal to d,then d= ___.(英汉小词典:parallel平行)