Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
352 views
in Sets, Relations and Functions by (93.6k points)
closed by
The set of all values of x satisfying `{x}=x[xx] " where " [xx]` represents greatest integer function `{xx}` represents fractional part of x

1 Answer

0 votes
by (94.6k points)
selected by
 
Best answer
Correct Answer - A::B
`{x}=[x]x`
`{x}=x(x-{x})=x^(2)-x{x}`
`implies {x}=(x^(2))/(1+x)`
Now `0 le {x} lt 1`
`implies (x^(2))/(1+x) ge 0`
`implies 1+x gt 0`
`implies x gt -1`
`(x^(2))/(1+x) lt 1`
`implies x^(2) lt 1 +x`
`implies x^(2) -x-1 lt 0`
`implies (1-sqrt(5))/(2) lt x lt (1+sqrt(5))/(2)`
Given equation again can be written as
`x-[x]=x[x]`
`(x)/(1+x)=[x]=lambda`
`x=(lambda)/(1-lambda)`
`(1-sqrt(5))/(2) lt (lambda)/(1-lambda) lt (1+sqrt(5))/(2)`
` implies (-1-sqrt(5))/(2) lt lambda lt (sqrt(5)-1)/(2)`
`lambda=0 implies x=0`
`lambda= -1 implies x=(-1)/(2)`

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...