show that the points (1,-1), (-1,-5) and (2,1) lies on a straight line. Use determinant. Prove by graphing. graphing is easy but what about determinant?

Question

sriram · Answer

i guess u show that the area of the triangle formed by 3 points is calculated using determinants

sriram · Answer

it looks smth like this
   
    1    x1      y1
     1    x2     y2     =2 * Area=0(here)
    1     x3     y3

sriram · Answer

x1 y1 ....are the coordinates in the question.
i hope you understood

anonymous · Answer

If [x1 y1 1, x2 y2 1, x3 y3 1] = 0  -> colinear.

anonymous · Answer

is it also the same in solving the concurrent line?

sriram · Answer

yep u can say lines made by selecting any 2 points r concurrent, hence points are in 1 line.

sriram · Answer

by concurrent here i meant u get the same equation for the line both the times

anonymous · Answer

thanks..