1.

If `a+b+c=0 and |a|=sqrt(37),|b|=3, |c|=4` then the angle between b and c isA. `30^(@)`B. `45^(@)`C. `60^(@)`D. `90^(@)`

Answer» Correct Answer - C
Given, `a+b+c=` and `|a|=sqrt(37), |b|=3` and `|c|=4`
Now, `a+b+c=0`
`implies a=-(b+c)`
`implies |a|^(2)=|-(b+c)|^(2)`
`implies |a|^(2)=|b|^(2)+|c|^(2)+2|b||c| cos theta`
`=9+16+24 cos theta`
`implies 37=25+24 cos theta`
`implies 24 cos theta =12 implies theta = 60^(@)`


Discussion

No Comment Found

Related InterviewSolutions