3 Views

Question : If $x+\frac{1}{x}=-2$, then what is the value of $x^7+x^{-7}+x^2+x^{-2} ?(\mathrm{x}<0)$

Option 1: 4

Option 2: 2

Option 3: 1

Option 4: 0


Team Careers360 15th Jan, 2024
Answer (1)
Team Careers360 20th Jan, 2024

Correct Answer: 0


Solution : $x+\frac{1}{x}=-2$
$⇒x^2+1=-2x$
$⇒x^2+2x+1=0$
$⇒(x+1)^2 = 0$
$\therefore x = -1$
By putting $x=-1$, we get,
$x^7+x^{-7}+x^2+x^{-2}=(-1)^7+(-1)^{-7}+(-1)^2+(-1)^{-2} = -2+2 = 0$
Hence, the correct answer is 0.

How to crack SSC CHSL

Candidates can download this e-book to give a boost to thier preparation.

Download Now

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
GRE ® Registrations 2024
Apply
Apply for GRE® Test now & save 10% with ApplyShop Gift Card | World's most used Admission Test for Graduate & Professional Schools
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books