已知曲线y=x^2+ax+b与2y=xy^3-1在点(1,-1)处有公共切线,求常数a,b

高手们帮我问一下,已知曲线y=x^2+ax+b与2y=xy^3-1在点(1,-1)处有公共切线,求常数a,b
最新回答
一川绿风

2024-11-04 13:43:10

简单计算一下即可,答案如图所示

容嬷嬷的春天

2024-11-04 11:04:46

如图

风夏了白雪

2024-11-04 02:11:33


微浅笑°

2024-11-04 10:57:20

(1,-1)
y=x^2+ax+b
-1=1+a+b
a+b=-2 (1)
y=x^2+ax+b
y' = 2x+a
y'|(1,-1) = 2+a
2y=xy^3-1
2y' = 3xy^2.y' + y^3
y' = y^3/(2-3xy^2)
y'|(1,-1) = -1/(2-3) = 1
2+a = 1
a=-1
from (1)
a+b=-2
-1+b=-2
b=-1
(a,b)=(-1,-1)