You are Here: Home >< Maths

Ocr C4 june 2011

Announcements Posted on
Would YOU be put off a uni with a high crime rate? First 50 to have their say get a £5 Amazon voucher! 27-10-2016
1. Hi.
I am a bit confused on this vector question 5(iii).
I got an answer of -i+j+k
But it was meant to be -2i+2j+2k.
I also only did this through trial and error and the mark scheme suggested that i use the dot product between the (position vector and direction vector) and the direction vector.
https://983c9f06eb1f75af6e83364e092b...20C4%20OCR.pdf
2. (Original post by SamuelN98)
Hi.
I am a bit confused on this vector question 5(iii).
I got an answer of -i+j+k
But it was meant to be -2i+2j+2k.
I also only did this through trial and error and the mark scheme suggested that i use the dot product between the (position vector and direction vector) and the direction vector.
https://983c9f06eb1f75af6e83364e092b...20C4%20OCR.pdf
We know from the given information that the position vector of lies on the line , so it must be true that the vector for some arbitrary value of . (Remember that as you input different values of s, you obtain different position vectors on the line.)

Now we know that this position vector must be perpendicular to the line, so the scalar product of the position vector , which we have obtained previously, and the direction vector of the line must be 0.

You will now obtain a value for the scalar which will give you the position vector of once inputted into the equation of your line.

Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: May 2, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read here first

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Chat with other maths applicants