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Question 105225: line L is perpendicular to a line with a slope -5. both lines contain the origine?
Answer by edjones(8007)   (Show Source):
You can put this solution on YOUR website! I assume you mean that L is a line that is perpendicular to another line that has a slope (m)=-5 and that L crosses the origin (0,0)
The slope of a line perpendicular to another line: m=-1/m[1]
So, m=-1/-5=1/5
m=-5 (0,0)
m=1/5 (0,0)
| Solved by pluggable solver: FIND a line by slope and one point |
What we know about the line whose equation we are trying to find out:
- it goes through point (0, 0)
- it has a slope of -5
First, let's draw a diagram of the coordinate system with point (0, 0) plotted with a little blue dot:
Write this down: the formula for the equation, given point  and intercept a, is
 (see a paragraph below explaining why this formula is correct)
Given that a=-5, and  , we have the equation of the line:
Explanation: Why did we use formula  ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point ( ,  ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (, ):  Here, we know a, , and , and do not know b. It is easy to find out:  . So, then, the equation of the line is:  .
Here's the graph:
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| Solved by pluggable solver: FIND a line by slope and one point |
What we know about the line whose equation we are trying to find out:
- it goes through point (0, 0)
- it has a slope of 0.2
First, let's draw a diagram of the coordinate system with point (0, 0) plotted with a little blue dot:
Write this down: the formula for the equation, given point and intercept a, is
(see a paragraph below explaining why this formula is correct)
Given that a=0.2, and , we have the equation of the line:
Explanation: Why did we use formula ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (, ) lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (, ): Here, we know a, , and , and do not know b. It is easy to find out: . So, then, the equation of the line is: .
Here's the graph:
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Here's a graph of both lines together.
Cool, huh!
Ed
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