# Math Help - equation of a plane :(

1. ## equation of a plane :(

find the equation of the plane:

perpendicular to the line through A(2,3,1) and B(5.7,2) and through A.

I get really confused and im not sure which equation to follow :S

thanks

2. Originally Posted by jd23
find the equation of the plane:

perpendicular to the line through A(2,3,1) and B(5.7,2) and through A.

I get really confused and im not sure which equation to follow :S

thanks

This question doesn't belong here but in the pre-algebra section. Anyway, the cross product $A\times B$ is always a vector perpendicular to both $A,\,B$ , so evaluate the plane through this vector and through $A$ .

Tonio

3. I'm still getting the wrong answer I firstly found the vector product which is then equal to the normal vector. Used that in the Cartesian equation. Where am I going wrong :s correct answer is 3x + 4y + z = 19