Math Homework. Do It Faster, Learn It Better.
Parallel Lines and Slopes
Parallel lines arecoplanarlines that do not intersect. In two dimensions, parallel lines have the sameslope.
我们可以把一条线平行的方程to a given line if we know a point on the line and an equation of the given line.
Example:
Write the equation of a line that passes through the pointand is parallel to the line
.
Parallel lines have the same slope.
The slope of the line with equationis. So, any line parallel tohas the same slope.
Now use thepoint-slope formto find the equation.
We have to find the equation of the line which has slopeand passes through the point. So, replacewith,with, andwith.
Use thedistributive property.
Addto each side.
Therefore, the lineis parallel to the lineand passes through the point.