11.若α,β为锐角,cos(α+β)=-$\frac{5}{13}$,sinβ=$\frac{3}{5}$,则sin(α+2β)=( )
| A. | $\frac{33}{65}$ | B. | -$\frac{63}{65}$ | C. | -$\frac{33}{65}$ | D. | $\frac{63}{65}$ |
10.若x>0,y>0,x+y=1,则$xy+\frac{2}{xy}$的最小值是( )
| A. | $\sqrt{2}$ | B. | $2\sqrt{2}$ | C. | $\frac{33}{2}$ | D. | $\frac{33}{4}$ |
9.设a,b为实数,则$\frac{1}{a}<\frac{1}{b}$成立的一个充分不必要条件是( )
| A. | b<a<0 | B. | a<b | C. | b(a-b)>0 | D. | a>b |
6.已知椭圆C:$\frac{{x}^{2}}{{a}^{2}}$+$\frac{{y}^{2}}{{b}^{2}}$=1(a>b>0),点M,N,F分别为椭圆C的左顶点、上顶点、左焦点,若∠MFN=∠NMF+90°,则椭圆C的离心率是( )
| A. | $\frac{\sqrt{5}-1}{2}$ | B. | $\frac{\sqrt{3}-1}{2}$ | C. | $\frac{\sqrt{2}-1}{2}$ | D. | $\frac{\sqrt{3}}{2}$ |
5.等差数列{an}前n项和为Sn,已知(1-a1007)5-2017(a1007-1)=1,(1-a1011)5-2017(a1011-1)=-1,则( )
| A. | S2017=2017,a1007>a1011 | B. | S2017=-2017,a1007>a1011 | ||
| C. | S2017=2017,a1007<a1011 | D. | S2017=-2017,a1007<a1011 |
4.与-420°终边相同的角是( )
0 236177 236185 236191 236195 236201 236203 236207 236213 236215 236221 236227 236231 236233 236237 236243 236245 236251 236255 236257 236261 236263 236267 236269 236271 236272 236273 236275 236276 236277 236279 236281 236285 236287 236291 236293 236297 236303 236305 236311 236315 236317 236321 236327 236333 236335 236341 236345 236347 236353 236357 236363 236371 266669
| A. | -120° | B. | 420° | C. | 660° | D. | 280° |