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
267 views
in Binomial Theorem by (42.5k points)
closed by

Show that the expansion of \(\Big(2x^2-\frac{1}{x}\Big)^{20}\) does not contain any term involving x9 .

1 Answer

+1 vote
by (44.7k points)
selected by
 
Best answer

For ,   \(\Big(2x^2-\frac{1}{x}\Big)^{20}\) 

a = 2x2 , b = \(\frac{-1}{x}\) and n=20 

We have a formula,

To get coefficient of x9 we must have, 

(x)40-3r = (x)9 

• 40 - 3r = 9 

• 3r = 31 

• r = 10.3333

As (20r) = (2010.3333) is not possible 

Therefore, the term containing x9 does not exist in the expansion of   \(\Big(2x^2-\frac{1}{x}\Big)^{20}\) 

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.

...