MAT 104 Quiz 10
Wednesday, September 29, 2004
1. Find an equation of the line passing the point (1,−2) with slope −2
Use the point-slope form of a line
y−y1=m(x−x1)
where m= slope = −2 and (x1, y1) = (1,−2). So we get
y−(−2) = −2(x−1)
or
y+ 2 = −2x+ 2
or
y=−2x
2. Find an equation of the line passing the point (2,1) that is parallel to the
line 2y=x−1.
Use the point-slope form a line
y−y1=m(x−x1)
where (x1, y1) = (2,1), and m= slope. Since our line is parallel to the
line 2y=x−1, our line will have the same slope. The slope of the line
2y=x−1 is 1
2, so our slope is m=1
2. So our equation is
y−1 = 1
2(x−2) =⇒2(y−1) = (x−2)
=⇒2y−2 = x−2
=⇒2y=x