6.抛物线y=-(x+2)2-3向右平移了3个单位,那么平移后抛物线的顶点坐标是( )
| A. | (-5,-3) | B. | (-2,0) | C. | (-1,-3) | D. | (1,-3) |
4.
如图,AB∥CD,∠1=70°,FG平分∠EFD,则∠2的度数是( )
| A. | 30° | B. | 35° | C. | 40° | D. | 70° |
3.在平面直角坐标系中,将点P(-1,1)向右平移3个单位长度,再向上平移4个单位长度得到点P′的坐标是( )
| A. | (2,5) | B. | (1,5) | C. | (1,-3) | D. | (-5,5) |
18.若将抛物线y=$\frac{1}{2}$x2先向左平移2个单位,再向下平移1个单位得到新的抛物线,则新抛物线的表达式是( )
0 282345 282353 282359 282363 282369 282371 282375 282381 282383 282389 282395 282399 282401 282405 282411 282413 282419 282423 282425 282429 282431 282435 282437 282439 282440 282441 282443 282444 282445 282447 282449 282453 282455 282459 282461 282465 282471 282473 282479 282483 282485 282489 282495 282501 282503 282509 282513 282515 282521 282525 282531 282539 366461
| A. | $y=\frac{1}{2}{(x+2)^2}-1$ | B. | $y=\frac{1}{2}{(x-2)^2}-1$ | C. | y=(x+2)2-1 | D. | $y=\frac{1}{2}(x-2)+1$ |