Posted by HongKit on Wednesday, October 17, 2012 at 12:14pm.
A vector equation for a given straight line is r = (i + 3j) + lambda (i  j)
Construct a vector equation for the line that does go through the point (1,2), and is perpendicular to r.
and
Determine the point of intersection of the two lines

math  Steve, Wednesday, October 17, 2012 at 3:18pm
you know that ij is perpendicular to ij since (1)(1) + (1)(1) = 1+1 = 0
so, i+2j + alpha(i  j) will do the trick
1lambda = 1 + alpha
3lambda = 2  alpha
intersect where lambda = 1/2 alpha = 1/2, at the point (1/2,5/2)
Answer This Question
Related Questions
 Precalc  A line in space has the vector equation shown here. Fill in the blanks...
 Math/Vectors  I need help on a homework problem. "Determine a vector equation ...
 Vectors  Determine the vector equation of a line passing through the point P(3,...
 Discrete Math: Equations of Line in a Plane  I'm stuck on these questions. Can ...
 Math: Equations of Line in a Plane  I'm stuck on these questions. Can you ...
 Writing this equation  how do I write the equation of a line perpendicular to ...
 Algebra 1  Write an equation in slopeintercept form for a line that passes ...
 Calc. for Reiny  this can be done by projections of two vector. recall that the...
 Math (Perpendicular equation)  Write the equation for the line through the ...
 Maths Vector Helpppp  The points A and B have position vectors, relative to the...
More Related Questions