Recent content by Josie Jones

mfb, thanks for moving the thread. I don't know how to find a perpendicular line or vector. I think it is a normal vector, but I have not been shown how to do this. I found this question in a book and am unsure how to proceed. thanks for your reply

Hi, I am really stuck! I need to find the equation of the plane through the line x=2y=3z perpendicular to the plan 5x+4y-3z=8. Can anyone give me any pointers of where to start with this? Not expecting a full solution, just an idea of where to start. THanks!

Hi, I am trying to simplify a double summation and was wondering if anyone would be able to help me. The sum is $$ \sum_{i=1}^{n-1} \sum_{j=i+1}^n a_i a_j $$ Is it possible to simplify it down and maybe lose one of the sigmas? Thank you in advance :)