Finding the scalar equation of a line

 
 
Scalar equation of a line blog post.jpeg
 
 
 

Formulas for the scalar equation of a line

To find the scalar equation of a line, we’ll use the formulas

???x=x_0+at???

???y=y_0+bt???

???z=z_0+ct???

where ???P_0(x_0,y_0,z_0)??? is a given point and ???v=\langle a,b,c\rangle??? is the given vector. The vector may also be in the format ???v=ai+bj+ck???.

Krista King Math.jpg

Hi! I'm krista.

I create online courses to help you rock your math class. Read more.

 
 
 

How to find the scalar equation of a line from the vector function and a point in space


 
Krista King Math Signup.png
 
Calculus 3 course.png

Take the course

Want to learn more about Calculus 3? I have a step-by-step course for that. :)

 
 

 
 

Finding the scalar equation from a point and the direction numbers

Example

Find the scalar equation of the line.

???P(2,3,1)???

???\langle2,-1,5\rangle???

Plugging the given point and the given vector into our formulas for ???x???, ???y??? and ???z???, we get

???x=2+2t???

???y=3-t???

???z=1+5t???

The scalar equation of the line is given by ???x=2+2t???, ???y=3-t??? and ???z=1+5t???.

 
Krista King.png
 

Get access to the complete Calculus 3 course