If three unit vectors a, b, c satisfy a+b+c=0 then the angle between a and b

#Mathematics

5794 Views

If three unit vectors a, b, c satisfy a+b+c=0 then the angle between a and b

Dileep kumar 12th Apr, 2019

Answer

Answer Later

Report

Answers (2)

Akash Pal 12th Apr, 2019

a+b+c=0

a+b=-c

|a+b|=|c|

a²+b²+2abcos∆=|c|²

1+1+2cos∆=1

cos∆= -1

∆=π

Like Share

Akash Pal 12th Apr, 2019

Hello Dileep, I am glad to help you.

a+b+c=0

a+b=-c

|a+b|=|c|

a²+b²+2abcos∆=|c|²

9+25+30cos∆=49

cos∆=1/2

∆=π/3 = 60°

I think your doubt is clear now.

All the best.

3 Comments

Like Share

Comments (3)

Dileep kumar

12th Apr, 2019

Thanks

Reply

Dileep kumar

12th Apr, 2019

But the answer given is 120

Reply

Akash Pal

12th Apr, 2019

The second one is the correct answer

Reply

Related Questions

If a, b,and c be three distinct real numbers in gp and a+b+c=xb then b cant be

142 Views

In a quadrilateral three angles are 55,65,and 105 then forth angle is

76 Views

Find a,b,c of orthogonal matrix 0 2b c a b c a b c

1501 Views

If a.b=a.c then how a is perpendicular to b-c?

480 Views

If n^ is a unit vector in the direction of vector A then vector n is equal to?

2291 Views

Applications for Admissions are open.

Woxsen University B.Sc. Admis...

Apply

Build Your Own Degree - Choose any 3 out of 8 Electives | 100% Plcament track | 100+ Global Partners | 200+ Industry Interactions

Symbiosis School for Liberal ...

Apply

Admissions open for BA/BSc. Liberal Arts (Honours) & BA / BSc. Liberal Arts (Honors) with Research

UPES B.Sc Admissions 2025

Apply

Ranked #46 amongst Universities in India by NIRF | Ranked #1 in Academic Reputation in India by QS World University Rankings

SRM University, Sonepat B.Sc ...

Apply

Upto 100% waiver in tuition fees for limited seats

Alliance University B.Sc. Adm...

Apply

Highest CTC 60.1 LPA | 800+ Recruitment Partners

Chandigarh University Admissi...

Apply

Ranked #1 Among all Private Indian Universities In QS Asia Rankings 2025 | Scholarships worth 210 CR

View All Application Forms

Trending Articles/News

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students

30,000+ Colleges

500+ Exams

1500+ E-books