函数f(x)对任意正实数x1,x2满足f(x1x2)=f(x1)+f(x2),已知f(8)=3,求f(√2)
问题描述:
函数f(x)对任意正实数x1,x2满足f(x1x2)=f(x1)+f(x2),已知f(8)=3,求f(√2)
答
f(x1x2)=f(x1)+f(x2),令x1=x2=√2可得:f(2)= f(√2)+ f(√2)=2 f(√2).令x1=x2=2可得:f(4)= f(2)+ f(2)=2 f(2).令x1=2,x2=4可得:f(8)= f(2)+ f(4),因为f(4)= =2 f(2)所以f(8)= 3f(2)因为f(2)= 2 f(√2). 所以f(8)...