1800-150-456-789
FlagBACK
Flag IIT JEE Entrance Exam> Find the range of 1/(x^2-x-1) . Please do...
question mark

Find the range of
1/(x^2-x-1) .
Please do answer this question.This is from the Relations and Functions in the book Cengage mathematics for jee mains
.

Kannan , 3 Years ago
Grade 11
anser 1 Answers
Kuldeepak Dhar Dwivedi

Last Activity: 3 Years ago

let y=1/(x²-x-1)
=>yx²-yx-y=1
=>yx²-yc-y-1=0
now
 if y is not equal to zero:
as x is real thus determinant of the function in terms of x must be greater than 0,
thus y²-4(y)(-y-1)≥0
=>y(y-4(-y-1))≥0 
=>Y(5y+4)≥0
=> Y belongs to (-infinity,-4/5]u(0, infinity)
Y=0 is not possible as for that denominator must be infinity but that will make the equation undefined
 thus, its range is (-infinity,-4/5]u(0, infinity)

Provide a better Answer & Earn Cool Goodies

star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Other Related Questions on iit jee entrance exam

question mark
My rank is 29k, General, should I opt for any state college cse branch or some Nits in which in which I am getting ECE , chemical, mechanics etc....
 
iit jee entrance exam
0 Answer Available

Last Activity: 2 Years ago

question mark
How is Ranquer Eduzone,comparing, Akash,Fitjee,Resonance,Naryana
iit jee entrance exam
0 Answer Available

Last Activity: 2 Years ago

question mark
Can class 9th students study syllabus class  of 11th 
iit jee entrance exam
3 Answers Available

Last Activity: 3 Years ago

question mark
Sum of series 2[n/2] ! [n/2]!/ n! [2Co-2C2+3C2....+[-1]^n[n+1]2Cn] where n is an even positive integer. Kindly provide solution of this question and how to generalise this. How do we know that which expansion will give this?
iit jee entrance exam
1 Answer Available

Last Activity: 3 Years ago

question mark
I m foreigner,How much mark i need to get into IIT?? 
 
iit jee entrance exam
1 Answer Available

Last Activity: 3 Years ago