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
+1 vote
91 views
in Determinants by (238k points)
closed by
What is the value of \(\begin{vmatrix} 1 & ω & 2ω^2 \\\ 2 & 2ω^2 & 4ω^3 \\\ 3 & 3ω^3 & 6ω^4 \end{vmatrix}\) where ω is the cube root of unity?

1 Answer

0 votes
by (240k points)
selected by
 
Best answer
Correct Answer - Option 1 : 0

Concept:

 ω is the cube root of unity.

⇒ω= 1 and 1 + ω + ω= 0

 

Calculations:

Given, ω is the cube root of unity.

⇒ω= 1 and 1 + ω + ω= 0

Consider,  \(\begin{vmatrix} 1 & ω & 2ω^2 \\\ 2 & 2ω^2 & 4ω^3 \\\ 3 & 3ω^3 & 6ω^4 \end{vmatrix}\) 

= 1(12 ω6 - 12 ω6) - ω (12 ω - 12 ω3) + 2ω(6 ω - 6ω2)

= 0 - ω [12 ωω  - 12 (1)] + 2ω[6 (1) - 6ω2]

= 12 ω2 + 12 ω - 12ω- 12ω4

= 12 ω  - 12ωω

= 12 ω  - 12 ω

= 0

Hence, the value of \(\begin{vmatrix} 1 & ω & 2ω^2 \\\ 2 & 2ω^2 & 4ω^3 \\\ 3 & 3ω^3 & 6ω^4 \end{vmatrix}\) where ω is the cube root of unity is zero.

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.

...