Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
Find the angle between the lines whose direction cosines has the relation
l
+
m
+
n
=
0
l + m + n = 0
l
+
m
+
n
=
0
and
2
l
2
+
2
m
2
−
n
2
=
0
2l^2 + 2m^2 - n^2 = 0
2
l
2
+
2
m
2
−
n
2
=
0
.
Browse the problem library