Please wait...
Contact Us
Contact
Need assistance? Contact us on below numbers

For Study plan details

93219 24448 / 89292 63204

10:00 AM to 7:00 PM IST all days.

For Franchisee Enquiry

81783 72169
OR

Chat with us on WhatsApp

or

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this number

93219 24448 / 99871 78554

Mon to Sat - 10 AM to 7 PM

Home / Doubts and Solutions/JEE/Mathematics

Sir pl solve qs no-5

qsnImg
Asked by shobhit 6th September 2018, 8:51 AM
Answered by Expert
Answer:
Angle between u and i is 60, we have
u.i=|u||i|cos 60 = |u|/2........(1)
|u|,|u-i|,|u-2i| are in GP, so
|u-i|2=|u|.|u-2i|
squaring both sides
[|u|2+|i|2 - 2.u.i]2=|u|2.[|u|2+4|i|2 - 4.u.i]
[|u|2+1- 2.|u|/2]2=|u|2.[|u|2+4 - 4.|u|/2]......from (1) and i is a unit vector
expand the identities, 
|u|2+2.|u|- 1 = 0 or |u|2=-(2±2√2)/2
|u|= √2-1

Answered by Expert 20th September 2018, 11:42 AM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Report an issue
Tags: vector-algebra
Previous Question
Next Question
Your answer has been posted successfully!

Free related questions

v=e^xyz(i+j+k) find curl v
25th January 2022, 9:56 AM
pls explain this answer ..
21st January 2022, 8:23 AM
 
3rd February 2022, 10:30 AM
if |A|=|B|=|A-B|, then find the angle b/w the two vectors
13th April 2022, 9:39 PM
Consider three vectors vector A, vector B, vector C. It is given that vector A and vector B lie in the x-y plane and the direction of vector C is along (+k^). Also, it is known that |vector A|=10 and |vector B|=6 units and the three vectors are related by the relation vector A=vector B - alpha(vector B X vector C), where alpha is some postive constant. Now, if only the magnitude of vector C is doubled, then what should the magnitude of vector B be, for which vector A remains unchanged (both in magnitude and direction)?
10th June 2022, 10:46 AM
RELATED STUDY RESOURCES :
JEE QUESTION ANSWERS

Browse free questions and answers by Chapters

Trending Tags

trigonometric equations Mole concept linear equations trigonometric ratios circle functions quadratic equation matrix operations integration equivalent resistance

Latest Questions

CBSE X Biology
What is enzyme  
Asked by Sureshgowdayd548 28th October 2020, 10:50 PM
JEE Main Mathematics
The following pseudocode is executed using the “Paragraph words” dataset. At the end of the execution, CountB captures the number of verbs with letter count less than the average letter count of verbs. But the pseudocode may have mistakes in one or more lines. Identify all such lines (if any). It is a Multiple Select Question (MSQ).  Error in Line 4  Error in Line 8  Error in Line 11  Error at Line 12  Error in Line 17  Error at Line 18  Error in Line 21 The following pseudocode is executed using the “Words” table. What will be the value of A at the end of the execution?
Asked by amaladelsingh 28th October 2020, 10:24 PM
CBSE X Biology
I want a brief clarity on Taxonomy
Asked by reenacharan2008 28th October 2020, 9:11 PM

Chat with us on WhatsApp