I really could do with some help on 9.b
Thanks
http://img7.imageshack.us/img7/5531/scan0004r.jpg
apolygise is image/link doesn't work, am posting this at school and imageshack is filtered, so I can't check...
I really could do with some help on 9.b
Thanks
http://img7.imageshack.us/img7/5531/scan0004r.jpg
apolygise is image/link doesn't work, am posting this at school and imageshack is filtered, so I can't check...
Yes, C=5, and now we have point N part c should be very simple, thank you for your help!
I kept trying to have ON and MN dotted = to zero to create simultaneous equations, with equations for the line MN's length equalling the length of OL.
It failed quite superbly, I greatly over complicated matters, would have been useful to know how many marks this question was.
If I didn't misread the question completely then the vectors $\displaystyle \overrightarrow{OL}$ and $\displaystyle \overrightarrow{OM}$ must be perpendicular. Therefore:
$\displaystyle (2,-3,3) \cdot (5,1,c) = 0~\implies~c=-\dfrac73$
The position vector of N is:
$\displaystyle \overrightarrow{ON} = \overrightarrow{OL} + \overrightarrow{OM} = \left(7,-2,\frac23 \right)$
The equation of the line is then:
$\displaystyle \vec r = \overrightarrow{OM} + t \cdot (\overrightarrow{ON} - \overrightarrow{OM})$
Plug in the vectors you know to get the equation of the line.