Vector addition and parallel vectors problem

[jeff einstein]

source of question: https://www.tes.com/teaching-resour...-questions-for-edexcel-1ma1-syllabus-12621082

Found this vector question by a google search, apparently a person has made this question and it seems almost impossible to solve it without using geometry. Even after using geometry the working out becomes really dirty. The main idea with this question is that ob is parralel to ac which is what defines the line MNC if ac and ob were not parallel then the question would truly be impossible.

Please help as soon as possible

 

[Greg Bernhardt]

Please show what you've tried thus far.

 

[jeff einstein]

Thank you so much for replying, here is the detailed solution to the problem

 

[Steve4Physics]

Do you really need a vector-based solution? The problem can be solved in a few lines of very simple (non-vector) working.

 

[jeff einstein]

i would be happy to know the other method please share it with us

 

[Steve4Physics]

i would be happy to know the other method please share it with us

The forum rules prevent me (quite rightly) from posting a solution to what is classified as a homework question.

But I guess a hint is ok: if you can identity two similar triangles, you can use simple proportionality.

Have a go and post your answer here.

 

[jeff einstein]

got it! thx for the help