Q.

Let f:R→R be any function. Define g:R→R by g(x)=|f(x)| for all x. Then g is           [2000]

1 onto if f is onto  
2 one-one if f is one-one  
3 continuous if f is continuous  
4 differentiable if f is differentiable  

Ans.

(3)

Let  h(x)=|x|

∴  g(x)=|f(x)|=h(f(x))

Since the composition of two continuous functions is continuous, therefore g is continuous if f is continuous.