15.函数$y=\frac{{\sqrt{x-2}}}{x-4}$的自变量的取值范围是( )
| A. | x≥2 | B. | x≥2且x≠4 | C. | x>2且x≠4 | D. | x≠4 |
11.式子$\sqrt{x+3}$有意义的条件是( )
| A. | x≥3 | B. | x>3 | C. | x≥-3 | D. | x>-3 |
8.把抛物线y=x2向右平移2个单位,向下平移5个单位得到的抛物线是( )
0 282177 282185 282191 282195 282201 282203 282207 282213 282215 282221 282227 282231 282233 282237 282243 282245 282251 282255 282257 282261 282263 282267 282269 282271 282272 282273 282275 282276 282277 282279 282281 282285 282287 282291 282293 282297 282303 282305 282311 282315 282317 282321 282327 282333 282335 282341 282345 282347 282353 282357 282363 282371 366461
| A. | y=x2+3 | B. | y=x2+7 | C. | y=(x+2)2-5 | D. | y=(x-2)2-5 |