Browse by Stream
QnA
Home
Search for Exam, Articles, Questions
QnA
get app
Go To Your Study Dashboard
  1. Home
  2. Try this! - Vector Algebra - JEE Main-4
# Engineering

Let \alpha \epsilon R and the three vectors

\vec{a}=\alpha\hat{i}+\hat{j}+3\hat{k} , \vec{a}=2\hat{i}+\hat{j}-\alpha \hat{k} and 

\vec{a}=\alpha \hat{i}-2\hat{j}+3 \hat{k} . Then the set 

S=\left \{{\alpha: \vec{a},\vec{b}\: \: and \: \: \vec{c}\: \: are\: \: coplanar }}{ \right \}

  • Option 1)

    is singleton

  • Option 2)

    is empty

  • Option 3)

    contains exactly two positive numbers

  • Option 4)

    contains exactly two numbers only one of which is positive

 

Answers (1)
V Vakul

\begin{vmatrix} \alpha & 1 & 3\\ 2 & 1 & -4\\ \alpha & -2 &-3 \end{vmatrix}=0

=>  3\alpha ^{2}+18=0

=>  \alpha \epsilon \phi


Option 1)

is singleton

Option 2)

is empty

Option 3)

contains exactly two positive numbers

Option 4)

contains exactly two numbers only one of which is positive

Similar Questions

Preparation Products

Knockout JEE Main April 2021 (One Month)

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 14000/- ₹ 6999/-
Buy Now
Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Test Series JEE Main April 2021

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 6999/- ₹ 4999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
JEE Main Rank Booster 2021

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 13999/- ₹ 9999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
Start Now
 
Exams
Articles
Questions