Question
Consider the following statements :
1. The function $$f\left( x \right) = $$ greatest integer $$ \leqslant x,\,x\, \in \,R$$ is a continuous function.
2. All trigonometric function are continuous on $$R.$$
Which of the statements given above is/are correct ?
A.
1 only
B.
2 only
C.
Both 1 and 2
D.
Neither 1 nor 2
Answer :
Neither 1 nor 2
Solution :
Here, greatest integer function $$\left[ x \right]$$ is discontinuous at its integral value of $$x,\,\cot \,x$$ and $${\text{cosec}}\,x\,$$ are discontinuous at $$0,\,\pi ,\,2\pi $$ etc. and $$\tan \,x$$ and $$sec \,x$$ are discontinuous at $$x = \frac{\pi }{2},\,\frac{{3\pi }}{2},\,\frac{{5\pi }}{2}$$ etc. Therefore the greatest integer function and all trigonometric function are not continuous for $$x\, \in \,R$$
Therefore, neither (1) nor (2) are true.