Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
How many distinct real solutions does the equation
cos
4
x
=
cos
2
x
\cos 4x = \cos 2x
cos
4
x
=
cos
2
x
have in the open interval
(
0
,
2
π
)
(0,2\pi)
(
0
,
2
π
)
? a) 4 b) 7 c) 5 d) 6
Browse the problem library