函数过p: 1 - (k²-1)-k²+2 = a
求导:f(x)' = 3x² - (k² - 1)
函数在p点得切线斜率为-1(与x-y+b=0垂直)
带入x = 1,f(x)' = -1
3 - (k² - 1) = -1 ,k² = 5
a = 1 - 4 - 5 + 2 = -6
(题目是f(x)=x³-(k²-1)x-k²+2 ,少了个x吧 )
函数过p: 1 - (k²-1)-k²+2 = a
求导:f(x)' = 3x² - (k² - 1)
函数在p点得切线斜率为-1(与x-y+b=0垂直)
带入x = 1,f(x)' = -1
3 - (k² - 1) = -1 ,k² = 5
a = 1 - 4 - 5 + 2 = -6
(题目是f(x)=x³-(k²-1)x-k²+2 ,少了个x吧 )