J JAsh New member Joined Jun 17, 2008 Messages 9 Sep 30, 2008 #1 determine the distance from the point A(2, -5) to the line r= (1,3) + t (-2,8) i could do it if instead of a line they gave another point, but i dont know how to do it like this help?
determine the distance from the point A(2, -5) to the line r= (1,3) + t (-2,8) i could do it if instead of a line they gave another point, but i dont know how to do it like this help?
D Deleted member 4993 Guest Sep 30, 2008 #2 Re: using vectors to find distance JAsh said: determine the distance from the point A(2, -5) to the line r= (1,3) + t (-2,8) i could do it if instead of a line they gave another point, but i dont know how to do it like this help? Click to expand... The parametric representation of line will give the co-ordinate of point on the line - when you assign a value of 't'. so for t = 0 you get (1,3) for t =1 you get (-1, 11) for t = 3 you get (-5, 27) all these are points on the line. So now draw a vector between these two points, define a unit vector along the line - take cross-product - and you have the distance. I am sure your textbook has some example problems just like this. If not try googling "distance line point". If you still have problem - write back showing your work, so that we know where to begin to help you.
Re: using vectors to find distance JAsh said: determine the distance from the point A(2, -5) to the line r= (1,3) + t (-2,8) i could do it if instead of a line they gave another point, but i dont know how to do it like this help? Click to expand... The parametric representation of line will give the co-ordinate of point on the line - when you assign a value of 't'. so for t = 0 you get (1,3) for t =1 you get (-1, 11) for t = 3 you get (-5, 27) all these are points on the line. So now draw a vector between these two points, define a unit vector along the line - take cross-product - and you have the distance. I am sure your textbook has some example problems just like this. If not try googling "distance line point". If you still have problem - write back showing your work, so that we know where to begin to help you.
