Functions Question 524

Question: If $ f(x)=\frac{\sin ([x]\pi )}{x^{2}+x+1} $ where [.] denotes the greatest integer function, then

Options:

A) f is one-one

B) f is not one-one and non-constant

C) f is a constant function

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

[c] $ f(x)=\frac{\sin [x]\pi }{x^{2}+x+1} $ Let $ [x]=n\in $ integer
$ \therefore \sin [x]\pi =0 $ Or $ f(x)=0 $ Hence, f(x) is constant function.