Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

If x^6=2 x^3-1 \text { and } x is not real then \sum_{r=1}^{50}\left(x^r+x^{2 r}\right)^3=

 

Option: 1

100


Option: 2

256


Option: 3

76


Option: 4

94


Answers (1)

best_answer

Given x6=2x3-1

x6-2x3+1=0

(x3-1)2=0

x3-1=0

x^3=1 \Rightarrow x=\omega, \omega^2 \quad x^r+x^{2 r}=\left\{\begin{array}{l} 2 \text { if } r \text { is a multiple of } 3 \\ -1 \text { if } r \text { is not a multiple of } 3 \end{array}\right.

On solving we get 94

 

Posted by

avinash.dongre

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Mains 2026 Registration LIVE: NTA JEE session 1 application, exam dates soon; city choice available
anam-khan

JEE Main 2026 exam city option not removed: NTA dismisses viral claim
anam-khan

JEE Main, NEET, CUET 2026: Claim on removal of exam city goes viral; what we know so far

Latest Question