设y=g(x)=a(x-b)(x-1)
1=ab
3=a(2-b)
解得:a=2 b=1/2
g(x)=2(x-(1/2))(x-1)=2[x^2-(3/2)x+(1/2)]=2x^2-3x+1
g'(x)=4x-3
g''(x)=4
-----------------------
感觉题目应该是存在a 使f(a)二阶导数等于4
考虑F(x)=f(x)-g(x)
然后用罗尔定理即可.
设y=g(x)=a(x-b)(x-1)
1=ab
3=a(2-b)
解得:a=2 b=1/2
g(x)=2(x-(1/2))(x-1)=2[x^2-(3/2)x+(1/2)]=2x^2-3x+1
g'(x)=4x-3
g''(x)=4
-----------------------
感觉题目应该是存在a 使f(a)二阶导数等于4
考虑F(x)=f(x)-g(x)
然后用罗尔定理即可.