Question

已知幂函数y=f(x)的图像经过点(2,(√2)/2),则f（9）=

Answer 1

f(x)=x^α

2^α=√2/2=2^(-1/2)

α=-1/2

f(x)=x^(-1/2)=1/√x

所以f(9)=1/3