ξ
0
1
2
P
则当p在(0,1)内增大时,( )
(Ⅰ)求sin(α+π)的值;
(Ⅱ)若角β满足sin(α+β)= ,求cosβ的值.
(Ⅰ)证明:AB1⊥平面A1B1C1;
(Ⅱ)求直线AC1与平面ABB1所成的角的正弦值.
(Ⅰ)求q的值;
(Ⅱ)求数列{bn}的通项公式.
(Ⅰ)设AB中点为M, 证明:PM垂直于y轴;
(Ⅱ)若P是半椭圆x2+ =1(x<0)上的动点,求△PAB面积的取值范围.
(Ⅰ)若f(x)在x=x1 ,x2(x1≠x2)处导数相等,证明:f(x1)+f(x2)>8−8ln2;
(Ⅱ)若a≤3−4ln2,证明:对于任意k>0,直线y=kx+a与曲线y=f(x)有唯一公共点.