抛物线y=2X²向左平移m个单位,再向下平移n个单位后解析式为:
y=2(X - m)² - n
将x = - 1时y = 1;x = 2时y = 3代入得:
2(m+1)² - n = 1
2(m-2)² - n = 3
解得:m = 1/3 n = 23/9
故所求解析式为:
y=2(X - 1/3)² - 23/9
= 2X² - 4/3X - 21/9
抛物线y=2X²向左平移m个单位,再向下平移n个单位后解析式为:
y=2(X - m)² - n
将x = - 1时y = 1;x = 2时y = 3代入得:
2(m+1)² - n = 1
2(m-2)² - n = 3
解得:m = 1/3 n = 23/9
故所求解析式为:
y=2(X - 1/3)² - 23/9
= 2X² - 4/3X - 21/9