Question

已知函数f(x)=x^3+ax^2+bx+c,曲线在点x=2处有极值

Answer 1

k=-3

f"(x)=3x*x+2ax+b

x=1 f"(x)=3+2a+b=k=-3

x=2 f"(X)=12+4a+b=0

a=-3 b=0

f"(x)=3x*x-6x=0

x1=0 x2=2

f(0)=c f(2)=c-4

极大值与极小值的差4