NDA 2018
- Exam
- NDA
- Year
- 2018
- Subject
- Mathematics
- Chapter
- Functions
NDA 2018 · Mathematics · Functions
Let [x] denote the greatest integer function. What is the number of...
Let denote the greatest integer function. What is the number of solutions of the equation in the interval
Options
- AZero (No solution)
- BOne
- CTwo
- DThree
Correct answer
B. One
Step-by-step solution
Given internal,
Case 1 : Let can't be taken in
Case 2 : Let roots are $\frac{4 \pm \sqrt{16-4}}{2}=\frac{4 \pm \sqrt{12}}{2}=2 \pm \sqrt{3}$
In internal $1 \leq x < 2,2 \pm \sqrt{3}$ are not the roots.
Case $3:$ Let $x=2\begin{aligned}
& {[\mathrm{x}]=2} \\
& \therefore \mathrm{x}^2-4 \mathrm{x}+2=0
\end{aligned}$$\frac{4 \pm \sqrt{16-8}}{2}=\frac{4 \pm \sqrt{8}}{2}=2 \pm \sqrt{2}\mathrm{x}=22 \pm \sqrt{2}\therefore\mathrm{x}=0$