(Ⅰ)求角B;
(Ⅱ)若b= ,a+c=ac,求△ABC的面积.
(Ⅰ)求证:平面AEC⊥平面PBC;
(Ⅱ)求直线AE与平面PAC所成角的大小.
(Ⅰ)求函数g(x)的解析式;
(Ⅱ)若h(x)=g(x)﹣λf(x)+1在[﹣1,1]上是增函数,求实数λ的取值范围.
如图,已知椭圆C: + =1(a>b>0)的离心率e= ,过点(0,﹣b),(a,0)的直线与原点的距离为 ,M(x0 , y0)是椭圆上任一点,从原点O向圆M:(x﹣x0)2+(y﹣y0)2=2作两条切线,分别交椭圆于点P,Q.
(Ⅰ)求椭圆C的方程;
(Ⅱ)若记直线OP,OQ的斜率分别为k1 , k2 , 试求k1k2的值.
(Ⅰ)求证:an+1<an;
(Ⅱ)求证: ≤an≤ .