以函数y=x^(1/2)为导数的函数f(x)图象过点(9,1)则f(x)=

问题描述:

以函数y=x^(1/2)为导数的函数f(x)图象过点(9,1)则f(x)=

f(x)=2/3*x^(3/2)+c
1=f(9)=2/3*27+c
c=-17
f(x)=2/3*x^(3/2)-17

假设f(x)=ax^n+C
则f(x)=an*x^(n-1)=y=x^(1/2)
n-1=1/2
an=1
n=3/2,a=2/3
f(x)=(2/3)x^(3/2)+C
过(9,1)
1=(2/3)*9^(3/2)+C=(2/3)*27+C
C=-17
f(x)=(2/3)x^(3/2)-17