Posted by Missy on .
Consider the line passing through the points (2, 1) and (2, 3). Find the parametric equation for y if x = t + 1.

Math 
MathMate,
Find the line that pass through the two points P1(2,1), and P2(2,3) in rectangular coordinates:
(x2x1)(yy1)=(y2y1)(xx1)
(22)(y1) = (31)(x2)
4(y1) = 2(x2)
2y+x=4
Solve for y in terms of x:
y=x/2 + 2
substitute x=t+1
y=(t+1)/2+2
=t/2 + 3/2
So:
x=t+1
y=t/2 + 5/2