10.不等式x2+ax+b<0的解集是(-1,3),则( )
A. | $\left\{\begin{array}{l}{a=2}\\{b=3}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{a=-2}\\{b=-3}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{a=1}\\{b=-6}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{a=3}\\{b=2}\end{array}\right.$ |
8.集合{x|0<|x-1|<3,x∈N}的真子集的个数有( )
A. | 7个 | B. | 8个 | C. | 15个 | D. | 16个 |
6.已知3sin2α+2sin2β=2sinα,则sin2α+sin2β的取值范围是( )
0 248581 248589 248595 248599 248605 248607 248611 248617 248619 248625 248631 248635 248637 248641 248647 248649 248655 248659 248661 248665 248667 248671 248673 248675 248676 248677 248679 248680 248681 248683 248685 248689 248691 248695 248697 248701 248707 248709 248715 248719 248721 248725 248731 248737 248739 248745 248749 248751 248757 248761 248767 248775 266669
A. | [-$\frac{3}{2}$,$\frac{1}{2}$] | B. | [0,$\frac{1}{2}$] | C. | [0,$\frac{4}{9}$] | D. | [$\frac{4}{9}$,$\frac{1}{2}$] |