Vector Equations to scalar equation and back

the problem is

- Find vector and parametric equations for the line with equation
*2x + y + 3 = 0*. - Determine a scalar equation for the line that passes through the point
*(-1, 5)* and has direction vector *http://mathhelpforum.com/MCV4UPU02/M...es%2Fvec-m.gif = (1, −3)*.

I am taking this coarse online and the content is no help please show me how it is done

Thanks

Re: Vector Equations to scalar equation and back

FlammingKnife

consider the line in 2D ax+by+c=0. Then the vector (-b,a) is always // to this line. you must know this....

to find the parametric equation of a line you need the vector // to the line and one point of the line.

in your case get one point of the line...example put x = 1 and find the y = -5

therefore the parametric equations of the line 2x+y+3=0 are x= 1-t and y = -5 +2t.

you may work similarly for the second question

MINOAS