15.已知在平面直角坐标系中,点M到x轴的距离为1,到y轴的距离为2,并且点M在第三象限,则点M的坐标为( )
| A. | (2,-1) | B. | (-2,-1) | C. | (-1,2) | D. | (1,-2) |
12.抛物线y=x2-(m-2)x+m+3的顶点在y轴上,则m的值为( )
0 282123 282131 282137 282141 282147 282149 282153 282159 282161 282167 282173 282177 282179 282183 282189 282191 282197 282201 282203 282207 282209 282213 282215 282217 282218 282219 282221 282222 282223 282225 282227 282231 282233 282237 282239 282243 282249 282251 282257 282261 282263 282267 282273 282279 282281 282287 282291 282293 282299 282303 282309 282317 366461
| A. | -3 | B. | 3 | C. | -2 | D. | 2 |