Functions Question 379

Question: If $ f(x)={\log_{a}}x $ and $ F(x)=a^{x} $ , then $ F

[f(x)] $ is [SCRA 1996]

Options:

A) $ f[F(x)] $

B) $ f[F(2x)] $

C) $ F|f(2x)| $

D) $ F[(x)] $

Show Answer

Answer:

Correct Answer: A

Solution:

$ F,[f(x)]=F,({\log_{a}}x)={a^{{\log_{a}}x}}=x $ $ f,[F,(x)]=f(a^{x})={\log_{a}}a^{x}=x,{\log_{a}}a=x $ .