14.曲线y=a$\sqrt{x}$(a>0)与曲线y=ln$\sqrt{x}$有公共点,且在公共点处的切线相同,则a的值为( )
| A. | e | B. | e2 | C. | $\frac{1}{{e}^{2}}$ | D. | $\frac{1}{e}$ |
13.已知向量$\overrightarrow{a}$,$\overrightarrow{b}$满足$\overrightarrow{a}$•$\overrightarrow{b}$=0,|$\overrightarrow{a}$|=2,|$\overrightarrow{b}$|=3,则|3$\overrightarrow{a}$-2$\overrightarrow{b}$|=( )
| A. | 0 | B. | 6$\sqrt{2}$ | C. | 36 | D. | 72 |
12.已知复数z足zi=-1+i,则z等于( )
| A. | -1-i | B. | 1-i | C. | -1+i | D. | 1+i |
10.已知函数f(x)=sin(ωx+φ)(ω>0)图象的两条相邻的对称轴的距离为$\frac{π}{3}$.若角φ的终边经过点P(1,-2),则f($\frac{7π}{3}$)等于( )
0 227259 227267 227273 227277 227283 227285 227289 227295 227297 227303 227309 227313 227315 227319 227325 227327 227333 227337 227339 227343 227345 227349 227351 227353 227354 227355 227357 227358 227359 227361 227363 227367 227369 227373 227375 227379 227385 227387 227393 227397 227399 227403 227409 227415 227417 227423 227427 227429 227435 227439 227445 227453 266669
| A. | $\frac{2\sqrt{5}}{5}$ | B. | $\frac{\sqrt{5}}{5}$ | C. | -$\frac{2\sqrt{5}}{5}$ | D. | -$\frac{\sqrt{5}}{5}$ |