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# Perpendicular distance q watch

1. From this link, I don't understand 11iii, it says show the perpendicular distance from AB to the origin is 9(root)10/10. Is it asking me to find the distance from the midpoint of AB to the origin? I've done that and I just get the distance of (root)13, which is wrong, what do I do?

http://www.mei.org.uk/files/papers/c109ju_kusp.pdf

Thank you
3. (Original post by Magenta96)
From this link, I don't understand 11iii, it says show the perpendicular distance from AB to the origin is 9(root)10/10. Is it asking me to find the distance from the midpoint of AB to the origin? I've done that and I just get the distance of (root)13, which is wrong, what do I do?

Thank you
The midpoint doesn't have to have anything to do with it.

I haven't read the question but I expect you need to find the gradient of AB.

Now find the gradient of the line perpendicular to AB.

Find the equation of this line that passes through the origin.

Find where this line meets AB.

Now find the distance from the origin to the point of intersection.
4. (Original post by Mr M)
The midpoint doesn't have to have anything to do with it.

I haven't read the question but I expect you need to find the gradient of AB.

Now find the gradient of the line perpendicular to AB.

Find the equation of this line that passes through the origin.

Find where this line meets AB.

Now find the distance from the origin to the point of intersection.
Good guess; that's covered in the first two parts of the question.
5. (Original post by ghostwalker)
Good guess; that's covered in the first two parts of the question.
Ha the question hadn't even been attached when I made my post!

6. (Original post by Mr M)
Ha the question hadn't even been attached when I made my post!

Thanks, I tried this way and it worked If I'd only annotated the diagram with what info I had it would've been a lot easier to see what they were asking me to find!
7. (Original post by Magenta96)
Thanks, I tried this way and it worked
Good.

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