15.直三棱柱ABC-A1B1C1中,∠BCA=90°,M是AB的中点,BC=CA=CC1,则C1M与面BCC1B1所成的角的正弦值为( )
| A. | $\frac{\sqrt{5}}{5}$ | B. | $\frac{\sqrt{6}}{6}$ | C. | $\frac{2\sqrt{5}}{5}$ | D. | $\frac{\sqrt{30}}{6}$ |
13.平面向量$\overrightarrow{a}$与$\overrightarrow{b}$的夹角等于$\frac{π}{3}$,|$\overrightarrow{a}$|=1,|$\overrightarrow{b}$|=2,则$\overrightarrow{a}$+$\overrightarrow{b}$与$\overrightarrow{a}$-$\overrightarrow{b}$的夹角的余弦值等于( )
| A. | $\frac{\sqrt{21}}{7}$ | B. | $\frac{1}{7}$ | C. | -$\frac{1}{7}$ | D. | -$\frac{\sqrt{21}}{7}$ |
12.阅读如图所示的程序框图,运行相应的程序,则输出的k的值是( )

| A. | 3 | B. | 4 | C. | 5 | D. | 6 |
11.运行如图所示的程序,输出的结果是( )

| A. | 5 | B. | 6 | C. | 15 | D. | 21 |
10.过点(1,0)且与直线x-y+2=0垂直的直线方程是( )
0 232270 232278 232284 232288 232294 232296 232300 232306 232308 232314 232320 232324 232326 232330 232336 232338 232344 232348 232350 232354 232356 232360 232362 232364 232365 232366 232368 232369 232370 232372 232374 232378 232380 232384 232386 232390 232396 232398 232404 232408 232410 232414 232420 232426 232428 232434 232438 232440 232446 232450 232456 232464 266669
| A. | x-y+1=0 | B. | x-y-1=0 | C. | x+y+1=0 | D. | x+y-1=0 |