Consider the planes 4x15x22x328 3x15x24x314 Find a point P t
Consider the planes
4x1+5x2+2x3=28
3x15x2+4x3=14
Find a point P that is on both planes. P:
Find a vector v that is parallel to both planes. v=
Find a vector equation for the intersection of the two planes in the form x(t)=.(............) + t(.........)
Solution
4x1+5x2+2x3=28
3x15x2+4x3=14
fix x3 =0
4x1+5x2=28
3x15x2=14
add
4x1+5x2 +3x15x2=-28+14
7x1=-14
x1=-2
4x1+5x2=28
4(-2)+5x2=28
5x2=20
x2=4
point P that is on both planes. P:(x1,x2,x3)=(-2,-4,0)
normal of 4x1+5x2+2x3=28 is n1=<4,5,2>
normal of 3x15x2+4x3=14 is n2=<3,-5,4>
vector v that is parallel to both planes. v=n1 x n2
v=<(5*4) -((-5)*2) ,(3*2)-(4*4) ,(4*(-5))-(3*5)>
v=<30 ,-10 ,-35>
vector v that is parallel to both planes. v=<30 ,-10 ,-35>
vector equation for the intersection of the two planes in the form r(t)=.(-2,-4,0)+ t<30 ,-10 ,-35>
